Land use can cause significant impacts on ecosystems and natural resources. To assess these impacts using life cycle assessment (LCA) and ensure adequate decision-making, comprehensive national inventories of land occupation and transformation flows are required. Here, we aim at developing globally differentiated inventories of land use flows that can be used for primary use in life cycle impact assessment or national land planning.
Methods
Using publicly available data and inventory techniques, national inventories for several land use classes were developed. All land use classes were covered with the highest retrievable level of disaggregation within urban, forestry, agriculture and other land use classes, thus differentiating 21 land use classes. For illustrating the application of this newly developed inventory, two different application settings relevant to life cycle impact assessment were considered: the calculation of global normalisation references for 11 land use impact indicators related to soil quality assessment (adopting the methods recommended by the EU Commission) and the determination of generic globally applicable characterisation factors (CFs) resulting from aggregation of country-level CFs for situations for use when land use location is unknown.
Results and discussion
We built national inventories of 21 land occupation and 17 land transformation flows for 225 countries in the world for the reference year 2010. Cross-comparisons with existing inventories of narrower scopes attested its consistency. Detailed analyses of the calculated global normalisation references for the 11 land use impact categories showed different patterns across the land use impact indicators for each country, thus raising attention on key land use impacts specific to each country. Furthermore, the upscaling of country-level CFs to global generic CFs using the land use inventory revealed discrepancies with other alternative approaches using land use data at different resolutions.
Conclusions
In this study, we made a first attempt at developing national inventories of land use flows with sufficient disaggregation level to enable the calculation of normalisation references and differentiated impacts. However, the findings also demonstrated the need to refine the consistency of the inventory, particularly in the combination of land cover and land use data, which should be harmonised in future studies, and to expand it with differentiated coverage of more land use flows relevant to impact assessment.
The synthesis of (4,5,6-13C)-deoxymannojirimycin is described. The route employed is based on Sharpless asymmetric epoxidation of (1,2,3-13C)(E)-2,4-pentadien-1-ol and uses ring-closing metathesis as a key step. The labeled compound may be easily used for protein-binding experiments using NMR spectroscopic methods. 相似文献
Photosystem II, the oxygen-evolving complex of photosynthetic organisms, includes an intriguingly large number of low molecular weight polypeptides, including PsbM. Here we describe the first knock-out of psbM using a transplastomic, reverse genetics approach in a higher plant. Homoplastomic Delta psbM plants exhibit photoautotrophic growth. Biochemical, biophysical, and immunological analyses demonstrate that PsbM is not required for biogenesis of higher order photosystem II complexes. However, photosystem II is highly light-sensitive, and its activity is significantly decreased in Delta psbM, whereas kinetics of plastid protein synthesis, reassembly of photosystem II, and recovery of its activity are comparable with the wild type. Unlike wild type, phosphorylation of the reaction center proteins D1 and D2 is severely reduced, whereas the redox-controlled phosphorylation of photosystem II light-harvesting complex is reversely regulated in Delta psbM plants because of accumulation of reduced plastoquinone in the dark and a limited photosystem II-mediated electron transport in the light. Charge recombination in Delta psbM measured by thermoluminescence oscillations significantly differs from the 2/6 patterns in the wild type. A simulation program of thermoluminescence oscillations indicates a higher Q(B)/Q(-)(B) ratio in dark-adapted mutant thylakoids relative to the wild type. The interaction of the Q(A)/Q(B) sites estimated by shifts in the maximal thermoluminescence emission temperature of the Q band, induced by binding of different herbicides to the Q(B) site, is changed indicating alteration of the activation energy for back electron flow. We conclude that PsbM is primarily involved in the interaction of the redox components important for the electron flow within, outward, and backward to photosystem II. 相似文献
Given the variable protective efficacy provided by Mycobacterium bovis BCG (Bacillus Calmette-Guérin), there is a concerted effort worldwide to develop better vaccines that could be used to reduce the burden of tuberculosis. Recombinant BCG (rBCG) are vaccine candidates that offer some potential in this area. In this paper, we will discuss the molecular methods used to generate rBCG, and the results obtained with some of these new vaccines as compared with the conventional BCG vaccine in diverse animal models. Tuberculosis vaccine candidates based on rBCG are promising candidates, and some of them are now being tested in clinical trials. 相似文献
Human RNase6 is a small cationic antimicrobial protein that belongs to the vertebrate RNaseA superfamily. All members share a common catalytic mechanism, which involves a conserved catalytic triad, constituted by two histidines and a lysine (His15/His122/Lys38 in RNase6 corresponding to His12/His119/Lys41 in RNaseA). Recently, our first crystal structure of human RNase6 identified an additional His pair (His36/His39) and suggested the presence of a secondary active site.
Methods
In this work we have explored RNase6 and RNaseA subsite architecture by X-ray crystallography, site-directed mutagenesis and kinetic characterization.
Results
The analysis of two novel crystal structures of RNase6 in complex with phosphate anions at atomic resolution locates a total of nine binding sites and reveals the contribution of Lys87 to phosphate-binding at the secondary active center. Contribution of the second catalytic triad residues to the enzyme activity is confirmed by mutagenesis. RNase6 catalytic site architecture has been compared with an RNaseA engineered variant where a phosphate-binding subsite is converted into a secondary catalytic center (RNaseA-K7H/R10H).
Conclusions
We have identified the residues that participate in RNase6 second catalytic triad (His36/His39/Lys87) and secondary phosphate-binding sites. To note, residues His39 and Lys87 are unique within higher primates. The RNaseA/RNase6 side-by-side comparison correlates the presence of a dual active site in RNase6 with a favored endonuclease-type cleavage pattern.
General significance
An RNase dual catalytic and extended binding site arrangement facilitates the cleavage of polymeric substrates. This is the first report of the presence of two catalytic centers in a single monomer within the RNaseA superfamily. 相似文献
Impaired angiogenesis leads to long-term complications and is a major contributor of the high morbidity in patients with Diabetes Mellitus (DM). Methylglyoxal (MGO) is a glycolysis byproduct that accumulates in DM and is detoxified by the Glyoxalase 1 (Glo1). Several studies suggest that MGO contributes to vascular complications through mechanisms that remain to be elucidated. In this study we have clarified for the first time the molecular mechanism involved in the impairment of angiogenesis induced by MGO accumulation.Angiogenesis was evaluated in mouse aortic endothelial cells isolated from Glo1-knockdown mice (Glo1KD MAECs) and their wild-type littermates (WT MAECs). Reduction in Glo1 expression led to an accumulation of MGO and MGO-modified proteins and impaired angiogenesis of Glo1KD MAECs. Both mRNA and protein levels of the anti-angiogenic HoxA5 gene were increased in Glo1KD MAECs and its silencing improved both their migration and invasion. Nuclear NF-?B-p65 was increased 2.5-fold in the Glo1KD as compared to WT MAECs. Interestingly, NF-?B-p65 binding to HoxA5 promoter was also 2-fold higher in Glo1KD MAECs and positively regulated HoxA5 expression in MAECs. Consistent with these data, both the exposure to a chemical inhibitor of Glo1 “SpBrBzGSHCp2” (GI) and to exogenous MGO led to the impairment of migration and the increase of HoxA5 mRNA and NF-?B-p65 protein levels in microvascular mouse coronary endothelial cells (MCECs).This study demonstrates, for the first time, that MGO accumulation increases the antiangiogenic factor HoxA5 via NF-?B-p65, thereby impairing the angiogenic ability of endothelial cells. 相似文献