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11.
Bioenergy could play a major role in decarbonizing energy systems in the context of the Paris Agreement. Large-scale bioenergy deployment could be related to sustainability issues and requires major infrastructure investments. It, therefore, needs to be studied carefully. The Bioenergy and Land Optimization Spatially Explicit Model (BLOEM) presented here allows for assessing different bioenergy pathways while encompassing various dimensions that influence their optimal deployment. In this study, BLOEM was applied to the Brazilian context by coupling it with the Brazilian Land Use and Energy Systems (BLUES) model. This allowed investigating the most cost-effective ways of attending future bioenergy supply projections and studying the role of recovered degraded pasture lands in improving land availability in a sustainable and competitive manner. The results show optimizing for limiting deforestation and minimizing logistics costs results in different outcomes. It also indicates that recovering degraded pasture lands is attractive from both logistics and climate perspectives. The systemic approach of BLOEM provides spatial results, highlighting the trade-offs between crop allocation, land use and the logistics dynamics between production, conversion, and demand, providing valuable insights for regional and national climate policy design. This makes it a useful tool for mapping sustainable bioenergy value chain pathways.  相似文献   
12.
The “Framework Messel” formulates regulations, recommendations and instructions for planning and carrying out palaeontological excavations in the Messel pit. The excavation of fossils in the Land Hessen is to some extent controlled by the Monument Protection Law. Therefore, the Framework was developed in close cooperation with the Land Monument Office. Administrative, scientific and organizational conditions for the excavations in the Middle Eocene oil-shales of Messel are listed. Instructional pamphlets explain technical details regarding methods of documentation, excavation and preparation of finds and results.  相似文献   
13.
The chromophore free apoprotein of neocarzinostatin was coupled to monoclonal IgG1 antibody using N-Succinimidyl 3-(2-pyridyldithio)-propionate as heterobifunctional reagent. After coupling active chromophore was reassociated with the apoprotein. We present here experimental evidence that the hybrid protein retains biological activity as measured by the degradation of T2-DNA and bacteriostatic action.  相似文献   
14.
Growing cells of Fusarium oxysporum f.sp. vasinfectum (ATCC 7808) formed 3-acetoxyscirpene-4,15-diol from anguidine (4,15-diacetoxyscirpene-3-ol) by way of the intermediates triacetoxyscirpene, 3,4-diacetoxyscirpene-15-ol and 3,15-diacetoxyscirpene-4-ol. The new 3-acetoxy analog was found to be less active than anguidine and the other monoacetoxy derivatives when tested against a series of fungal strains and against HeLa cells in vitro.  相似文献   
15.
A DNA fragment coding for the E. coli phoA signal peptide was synthesized and inserted into the expression vector pKK223-3. A single HindIII restriction site is located just at the end of the signal sequence. A gene coding for the proteinase inhibitor hirudin, which has previously been synthesized, was inserted into this HindIII site. The hybrid protein was expressed under control of the tac-promoter and secreted into the periplasm of E. coli. From the periplasmic fraction two processed proteins were isolated. One of these was identical with desulfatohirudin and also had similar biological properties.  相似文献   
16.
17.
Abe M  Tsai SY  Jin SG  Pfeifer GP  Szabó PE 《PloS one》2011,6(8):e23848
Mammalian germ cells undergo global reprogramming of DNA methylation during their development. Global DNA demethylation occurs around the time when the primordial germ cells colonize the embryonic gonads and this coincides with dynamic changes in chromatin composition. Global de novo DNA methylation takes place with remarkably different dynamics between the two sexes, prospermatogonia attaining methylation during fetal stages and oocytes attaining methylation postnatally. Our hypothesis was that dynamic changes in chromatin composition may precede or accompany the wave of global DNA de novo methylation as well. We used immunocytochemistry to measure global DNA methylation and chromatin components in male and female mouse fetal germ cells compared to control somatic cells of the gonad. We found that global DNA methylation levels sharply increased in male germ cells at 17.5 days post coitum, but remained low in female germ cells at all fetal stages. Global changes in chromatin composition: i, preceded global DNA methylation in fetal germ cells; ii, sex specifically occurred in male but not in female germ cells; iii, affected active and repressive histone marks and iv, included histone tail and histone globular domain modifications. Our data suggest that dynamic changes of chromatin composition may provide a framework for the pattern of male-specific de novo DNA methylation in prospermatogonia.  相似文献   
18.
Human Helicobacter pylori infection leads to multiple pathological consequences, including gastritis and adenocarcinoma. Although this association has led to the classification of H. pylori as a type 1 carcinogen, it is not clear if additional nonhelicobacter gastric microbiota play a role in these diseases. In this study, we utilized either specific pathogen-free C57BL/6 mice (B6.SPF) or mice colonized with altered Schaedler flora (B6.ASF) to evaluate the role of nonhelicobacter gastric microbiota in disease development after Helicobacter felis infection. Despite similar histological changes, H. felis persisted in B6.ASF stomachs, while H. felis could no longer be detected in the majority of B6.SPF mice. The B6.SPF mice also acquired multiple Lactobacillus spp. in their stomachs after H. felis infection. Our data indicate that potential mechanisms responsible for the ineffective H. felis clearance in the B6.ASF model include the absence of new gastric microbiota to compete for the gastric niche, the lack of expression of new gastric mucins, and a reduced ratio of H. felis–specific IgG2c:IgG1 serum antibodies. These data suggest that although H. felis is sufficient to initiate gastric inflammation and atrophy, bacterial eradication and the systemic immune response to infection are significantly influenced by pre-existing and acquired gastric microbiota.  相似文献   
19.
Both the disulphide bond (Cys192-Cys199) and the proline-rich motif (Pro193ProAsnPro196) in the long loop connecting the alpha4-alpha5 transmembrane hairpin of the Cry4Aa mosquito-larvicidal protein have been found to be unique among the Bacillus thuringiensis Cry delta-endotoxins. In this study, their structural requirements for larvicidal activity of the Cry4Aa toxin were investigated. C192A and C199A mutant toxins were initially generated and over-expressed in Escherichia coli cells as 130-kDa protoxins at levels comparable to that of the wild-type toxin. When their activities against Aedes aegypti larvae were determined, Escherichia coli cells expressing each mutant toxin retained the high-level toxicity. Further mutagenic analysis of the PPNP motif revealed that an almost complete loss in larvicidal activity was observed for the C199A/P193A double mutant, whereas a small reduction in toxicity was shown for the C199A/P194A and C199A/P196A mutants. Increasing the flexibility of the alpha4-alpha5 loop through C199A/P193G, C199A/P194G/P196A, C199A/P194A/P196G, and C199A/P194G/P196G mutations significantly decreased the larvicidal activity. Similar to the wild-type protoxin, all mutant toxins were structurally stable upon solubilisation and trypsin activation in carbonate buffer, pH 9.0. These findings are the first biological evidence for a structural function in larvicidal activity of the unique disulphide bridge as well as the proline-rich motif within the alpha4-alpha5 loop of the Cry4Aa toxin.  相似文献   
20.
The inhibition of protein tyrosine phosphatases by pervanadate, a potent activator of B- and T-cells through the induction of tyrosine phosphorylation and downstream signaling events in different activation cascades, efficiently induced apoptosis in lymphoid cell lines. Pervanadate-elicited apoptosis could be blocked by the tyrosine kinase inhibitor herbimycin A. This apoptotic process involved the activation of caspases 3, 8 and 9, the induction of mitochondrial permeability transition, the release of cytochrome C and the fragmentation of chromosomal DNA. T-cells lacking the CD95 receptor or caspase-8 and T-cells stably overexpressing a transdominant negative form of the adaptor protein FADD were still susceptible to pervanadate-induced apoptosis, excluding the involvement of the CD95 system or other FADD-dependent death receptors. The apoptotic program initiated by the inhibition of tyrosine phosphatases did not require the presence of the tyrosine kinase p56lck or phosphatase CD45, whereas Bcl-2 overexpression protected T-cells from pervanadate-induced cytochrome C release, caspase-8 cleavage and apoptosis.  相似文献   
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