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941.
Using the ecosystem services approach for better planning and conservation of urban green spaces: a Finland case study 总被引:6,自引:0,他引:6
Jari Niemelä Sanna-Riikka Saarela Tarja Söderman Leena Kopperoinen Vesa Yli-Pelkonen Seija Väre D. Johan Kotze 《Biodiversity and Conservation》2010,19(11):3225-3243
Ecosystem services are vital for humans in urban regions. However, urban development poses a great risk for the ability of
ecosystems to provide these services. In this paper we first address the most important ecosystem services in functional urban
regions in Finland. Well accessible and good quality recreational ecosystem services, for example, provided by urban nature,
are an important part of a high-quality living environment and important for public health. Vegetation of urban regions can
have a role in carbon dioxide sequestration and thus in climate change mitigation. For instance, estimates of carbon sinks
can be compared to total CO2 emissions of an urban region, and the municipality can aim at both increasing carbon sinks and decreasing CO2 emissions with proper land-use planning. Large and contiguous core nature areas, smaller green areas and ecological connections
between them are the essence of regional ecological networks and are essential for maintaining interconnected habitats for
species and thus biological diversity. Thus, both local and regional level ecological networks are vital for maintaining ecosystem
services in urban regions. The impacts of climate change coupled with land-use and land cover change will bring serious challenges
for maintaining ecosystem services in urban areas. Although not yet widely used in planning practices, the ecosystem services
approach can provide an opportunity for land-use planning to develop ecologically sustainable urban regions. Currently, information
on ecosystem services of urban regions is lacking and there is a need to improve the knowledge base for land-use planning. 相似文献
942.
The genetic material, deoxyribonucleic acid (DNA), contains information about the evolutionary history of life. Both the relationships
amongst organisms and the times of their divergence can be inferred from DNA sequences. Anthropological geneticists use DNA
sequences to infer the evolutionary history of humans and their primate relatives. We review the basic methodology used to
infer these relationships. We then review the anthropological genetic evidence for modern human origins. We conclude that
modern humans evolved recently in Africa and then left to colonize the rest of the world within the last 50,000 years, largely
replacing the other human groups that they encountered. Modern humans likely exchanged genes with Neanderthals prior to or
early during their expansion out of Africa. 相似文献
943.
944.
Yong Liu Ronglei Liu Liangchen Ye Jun Liang Fujun Xuan Qianghua Xu 《Hydrobiologia》2009,618(1):125-137
Portunus trituberculatus is a commercially important species widely spread in the East China Sea. Intraspecific variation of the mitochondrial DNA
cytochrome oxidase subunit I (mtDNA COI) gene was investigated in 213 individuals from six localities (Changjiang Estuary,
Shengsi Islands, Zhoushan Islands, Dongtou Islands, Dinghai Bay, and Quanzhou Bay) ranging from north (31°21′N) to south (24°55′N)
coastal waters of the East China Sea. Overall, a total of 27 mtDNA haplotypes and 21 variable sites were detected in the 787 bp
segment of COI gene. Analysis of mtDNA COI sequence data revealed that crabs from the six localities were characterized by
moderately high haplotypic diversity (h = 0.787 ± 0.026), while sequence divergence values between haplotypes were relatively low (π = 0.00241 ± 0.00098). Each population
was characterized by a single most frequent haplotype, shared among all six localities, and a small number of rare ones, typically
present in only one or two individuals and representative of a specific population. However, neither the neighbor-joining
tree nor the minimum spanning network (MSN) based on the haplotype data exhibited geographical patterns of the six populations.
Mismatch distribution analysis of P. trituberculatus individuals sampled from the six localities suggested that sudden population expansion might have occurred in CJ and SS population
that might be consistent with over-exploitation of the swimming crab. Analysis of molecular variance (AMOVA) and F
ST statistics showed that significant genetic differentiation existed among the SS, ZS, DT, DH, and QZ populations, suggesting
that gene flow might be reduced, even between the geographically close sites, despite the high potential of dispersal. The
possible causes of the observed genetic heterogeneity among the P. trituberculatus populations and the potential applications of the mtDNA COI marker in the artificial breeding and fisheries management are
discussed.
Handling editor: C. Sturmbauer 相似文献
945.
946.
Jean-Christophe Breitler Eveline Dechamp Claudine Campa Leonardo Augusto Zebral Rodrigues Romain Guyot Pierre Marraccini Hervé Etienne 《Plant Cell, Tissue and Organ Culture》2018,134(3):383-394
Genome editing, which is an unprecedented technological breakthrough, has provided a valuable means of creating targeted mutations in plant genomes. In this study, we developed a genomic web tool to identify all gRNA target sequences in the coffee genome, along with potential off-targets. In all, 8,145,748 CRISPR guides were identified in the draft genome of Coffea canephora corresponding to 5,338,568 different sequences and, of these, 4,655,458 were single, and 514,591 were covering exons. The proof of concept was established by targeting the phytoene desaturase gene (CcPDS) using the Agrobacterium tumefaciens transformation technique and somatic embryogenesis as the plant regeneration method. An analysis of the RNA-guided genome-editing events showed that 22.8% of the regenerated plants were heterozygous mutants and 7.6% were homozygous mutants. Mutation efficiency at the target site was estimated to be 30.4%. We demonstrated that genome editing by the CRISPR/Cas9 method is an efficient and reliable way of knocking out genes of agronomic interest in the coffee tree, opening up the way for coffee molecular breeding. Our results also showed that the use of somatic embryogenesis, as the method for regenerating genome-edited plants, could restrict the choice of targeted genes to those that are not essential to the embryo development and germination steps. 相似文献
947.
948.
Dingpei Long Weijian Lu Zhanzhang Hao Zhonghuai Xiang Aichun Zhao 《Transgenic research》2016,25(6):795-811
Efficient and inducible recombinase-mediated DNA excision is an optimal technology for automatically deleting unwanted DNA sequences, including selection marker genes. However, this methodology has yet to be established in transgenic silkworms. To achieve efficient and inducible FLP recombinase-mediated DNA excision in transgenic silkworms, one transgenic target strain (TTS) containing an FRT-flanked silkworm cytoplasmic actin 3 gene promoter (A3)-enhanced green fluorescent protein (EGFP) expression cassette, as well as two different types of FLP recombinase expression helper strains were generated. Then, the FLP recombinase was introduced into the TTS silkworms by pre-blastoderm microinjection and sexual hybridization. Successful recombinase-mediated deletion of the A3-EGFP expression cassette was observed in the offspring of the TTS, and the excision efficiencies of the FLP expression vector and FLP mRNA pre-blastoderm microinjection were 2.38 and 13.3 %, respectively. The excision efficiencies resulting from hybridization between the TTS and the helper strain that contained a heat shock protein 70 (Hsp70)-FLP expression cassette ranged from 32.14 to 36.67 % after heat shock treatment, while the excision efficiencies resulting from hybridization between the TTS and the helper strain containing the A3-FLP expression cassette ranged from 97.01 to 100 %. These results demonstrate that the FLP/FRT system can be used to achieve highly efficient and inducible post-integration excision of unwanted DNA sequences in transgenic silkworms in vivo. Our present study will facilitate the development and application of the FLP/FRT system for the functional analysis of unknown genes, and establish the safety of transgenic technologies in the silkworm and other lepidopteran species. 相似文献
949.
Systemic lupus erythematosus (SLE) is a chronic, multisystem autoimmune disease characterized by the differentiation of short- and long-lived immunoglobulin secreting plasma cells that secrete pathogenic autoantibodies. Ectopic germinal centers and plasma cells secreting autoantibodies have been observed in lupus nephritis kidneys. Candidate genetic susceptibility loci for SLE include genes that affect differentiation and survival of plasma cells, such as those that influence activation, proliferation, cytokine and chemokine secretion/responsiveness, and apoptosis of the T and B cells that are involved in humoral immunity generated in germinal centers, as well as genes that are involved in presentation and clearance of apoptotic material and autoantigens by antigen presenting cells and other phagocytes. Emerging data have demonstrated that B lymphocytes are active participants in humoral immune responses that lead to T-dependent and T-independent differentiation of immunoglobulin-secreting plasma cells by homotypic CD154-CD40 interactions as well as continued stimulation by B cell activating factor through B cell maturation antigen, B cell activating factor receptor and transmembrane activater. 相似文献
950.