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11.
Willows (Salix spp.) are a very diverse group of catkin-bearing trees and shrubs that are widely distributed across temperate regions of the globe.Some species respond well to being grown in short rotation coppice (SRC) cycles,which are much shorter than conventional forestry.Coppicing reinvigorates growth and the biomass rapidly accumulated can be used as a source of renewable carbon for bioenergy and biofuels.As SRC willows re-distribute nutrients during the perennial cycle they require only minimal nitro...  相似文献   
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Background  

Penicillium chrysogenum converts isopenicillin N (IPN) into hydrophobic penicillins by means of the peroxisomal IPN acyltransferase (IAT), which is encoded by the penDE gene. In silico analysis of the P. chrysogenum genome revealed the presence of a gene, Pc13g09140, initially described as paralogue of the IAT-encoding penDE gene. We have termed this gene ial because it encodes a protein with high similarity to IAT (IAL for IAT-Like). We have conducted an investigation to characterize the ial gene and to determine the role of the IAL protein in the penicillin biosynthetic pathway.  相似文献   
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In sub-Saharan Africa the highest overlap between malaria and HIV infections occurs in female adolescents. Yet control activities for these infections are directed to different target groups, using disparate channels. This reflects the lack of priority given to adolescents and the absence of an accepted framework for delivering health and health-related interventions to this high-risk group. In this paper it is argued that female adolescents require a continuum of care for malaria and HIV – prior to conception, during and after pregnancy and that this should be provided through adolescent services. The evidence for this conclusion is presented. A number of African countries are commencing to formulate and implement adolescent-friendly policies and services and disease control programs for malaria and HIV will need to locate their interventions within such programs to ensure widespread coverage of this important target group. Failure to prioritize adolescent health in this way will seriously limit the success of disease control programs for malaria and HIV prevention.  相似文献   
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Although an apoplastic pathway (the so‐called bypass flow) is implicated in the uptake of Na+ by rice growing in saline conditions, the point of entry of this flow into roots remains to be elucidated. We investigated the role of lateral roots in bypass flow using the tracer trisodium‐8‐hydroxy‐1,3,6‐pyrenetrisulphonic acid (PTS) and the rice cv. IR36. PTS was identified in the vascular tissue of lateral roots using both epifluorescence microscopy and confocal laser scanning microscopy. Cryo‐scanning electron microscopy and epifluorescence microscopy of sections stained with berberine‐aniline blue revealed that the exodermis is absent in the lateral roots. We conclude that PTS can move freely through the cortical layers of lateral roots, enter the stele and be transported to the shoot via the transpiration stream.  相似文献   
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The ATP-binding-cassette transmembrane transporters (ABC transporters) known from vertebrates belong to four major subfamilies: (1) the P- glycoproteins (Pgp); (2) the cystic fibrosis transmembrane conductance regulators (CFTR); (3) the Tap proteins encoded with the major histocompatibility complex of mammals; and (4) the peroxisomal membrane proteins. Both Pgp and CFTR have a structure suggesting a past internal gene duplication; a phylogenetic analysis indicated that these duplications occurred independently, while an independent tandem gene duplication occurred in the case of the Tap family. Both the Pgp and Tap proteins show evidence of relationship to bacterial ABC transporters lacking internal duplication, and both are significantly more closely related to the HlyB and MsbA families of transporters from purple bacteria than they are to ABC transporters from nonpurple bacteria. The simplest hypothesis to explain this observation is that eukaryotic Pgp and Tap genes are descended from a mitochondrial gene or genes that were subsequently translocated to the nuclear genome. The Pgp genes of eukaryotes are characterized by a remarkable degree of convergent evolution between the ATP-binding cassettes of their N- terminal and C-terminal halves, whereas no such convergence is seen between the two halves of CFTR genes or between the duplicated Tap genes. Exon 13 of the CFTR gene, which encodes a putative regulatory domain not found in other ABC transporters apart from CFTR, showed high levels of both synonymous and nonsynonymous difference in comparisons among different mammalian species, suggesting that this region is a mutational hot spot.   相似文献   
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The Endo F2gene was overexpressed in E.coli as a fusion protein joined to the maltose-binding protein. MBP-Endo F2was found in a highly enriched state as insoluble, inactive inclusion bodies. Extraction of the inclusion bodies with 20% acetic acid followed by exhaustive dialysis rendered the fusion protein active and soluble. MBP-Endo F2was digested with Factor Xaand purified on Q-Sepharose. The enzyme was homogeneous by SDS-PAGE, and appeared as a single symmetrical peak on HPLC. Analysis of the amino-terminus demonstrated conclusively that recombinant Endo F2was homogeneous and identical to the native enzyme.   相似文献   
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