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排序方式: 共有326条查询结果,搜索用时 78 毫秒
321.
Fabrice Duponchelle Victoria J. Isaac Carolina Rodrigues Da Costa Doria Paul A. Van Damme Guido A. Herrera-R Elizabeth P. Anderson Rivetla E.A. Cruz Marilia Hauser Theodore W. Hermann Edwin Agudelo César Bonilla-Castillo Ronaldo Barthem Carlos E.C. Freitas Carmen García-Dávila Aurea García-Vasquez Jean-François Renno Leandro Castello 《水产资源保护:海洋与淡水生态系统》2021,31(12):1087-1105
- The Amazon basin hosts the Earth's highest diversity of freshwater fish. Fish species have adapted to the basin's size and seasonal dynamics by displaying a broad range of migratory behaviour, but they are under increasing threats; however, no study to date has assessed threats and conservation of Amazonian migratory fishes.
- Here, the available knowledge on the diversity of migratory behaviour in Amazonian fishes is synthesized, including the geographical scales at which they occur, their drivers and timing, and life stage at which they are performed.
- Migratory fishes are integral components of Amazonian society. They contribute about 93% (range 77–99%) of the fisheries landings in the basin, amounting to ~US$436 million annually.
- These valuable fish populations are mainly threatened by growing trends of overexploitation, deforestation, climate change, and hydroelectric dam development. Most Amazonian migratory fish have key ecological roles as apex predators, ecological engineers, or seed-dispersal species. Reducing their population sizes could induce cascading effects with implications for ecosystem stability and associated services.
- Conserving Amazonian migratory fishes requires a broad portfolio of research, management, and conservation actions, within an ecosystem-based management framework at the basin scale. This would require trans-frontier coordination and recognition of the crucial importance of freshwater ecosystems and their connectivity.
- Existing areas where fishing is allowed could be coupled with a chain of freshwater protected areas. Management of commercial and subsistence species also needs fisheries activities to be monitored in the Amazonian cities and in the floodplain communities to allow assessments of the status of target species, and the identification of management units or stocks. Ensuring that existing and future fisheries management rules are effective implies the voluntary participation of fishers, which can be achieved by increasing the effectiveness and coverage of adaptive community-based management schemes.
322.
Matthew Levy Lorrie Gaschen Nathalie Rademacher Hermann Bragulla 《Veterinary radiology & ultrasound》2014,55(4):435-440
Ultrasound‐guided intraarticular injection of cervical articular process joints is a well‐established procedure in both humans and horses for neck pain resulting from osteoarthritis, but the technique has not been described in dogs. Aims of this study were to describe the ultrasonographic anatomy and landmarks for cervical articular process joint injections in the dog, develop a technique for articular process joint injections using these landmarks, and determine the accuracy of injections and factors that may influence it. Eleven canine cadavers were used and bilateral joint spaces from C2–3 to C7‐T1 were injected under ultrasound guidance with a blue radiopaque solution. A computed tomographic scan was acquired following each injection, and an injection score was assigned and compared with other patient‐specific factors. Of the 132 injections performed, 110 (83.3%) were intraarticular, 20 (15.1%) were periarticular within 5 mm, and 2 (1.5%) were periarticular beyond 5 mm from the joint. There was no significant difference in mean scores between dogs. Only C2–3 had a significantly lower mean score than any other joint. There was no significant correlation between injection score and any other factors measured. The transverse processes of the cervical vertebrae served as excellent ultrasonographic landmarks for identifying the cervical articular process joints in dogs regardless of the size of the dog or location along the vertebrae. Accuracy of ultrasound‐guided intraarticular process joint injection was 83% in dogs and similar to published techniques in horses. Further studies are needed to examine the safety and efficacy of this procedure in live animals. 相似文献
323.
Calarese DA Scanlan CN Zwick MB Deechongkit S Mimura Y Kunert R Zhu P Wormald MR Stanfield RL Roux KH Kelly JW Rudd PM Dwek RA Katinger H Burton DR Wilson IA 《Science (New York, N.Y.)》2003,300(5628):2065-2071
Human antibody 2G12 neutralizes a broad range of human immunodeficiency virus type 1 (HIV-1) isolates by binding an unusually dense cluster of carbohydrate moieties on the "silent" face of the gp120 envelope glycoprotein. Crystal structures of Fab 2G12 and its complexes with the disaccharide Manalpha1-2Man and with the oligosaccharide Man9GlcNAc2 revealed that two Fabs assemble into an interlocked VH domain-swapped dimer. Further biochemical, biophysical, and mutagenesis data strongly support a Fab-dimerized antibody as the prevalent form that recognizes gp120. The extraordinary configuration of this antibody provides an extended surface, with newly described binding sites, for multivalent interaction with a conserved cluster of oligomannose type sugars on the surface of gp120. The unique interdigitation of Fab domains within an antibody uncovers a previously unappreciated mechanism for high-affinity recognition of carbohydrate or other repeating epitopes on cell or microbial surfaces. 相似文献
324.
Mahmoud A. Hamza Professor Ahmed M. El-Tabey Shehata Hermann Stegemann 《Plant foods for human nutrition (Dordrecht, Netherlands)》1987,36(4):253-262
A number of national dishes are prepared from the dry seeds of faba bean by soaking, germination (nabet), cooking (bisara and medammis) or frying a dough (falafel). Soaking (12 h) decreased the intensity of bands in the standard PAGE and increased the charge heterogeneity of neutral proteins in PAGIF. Germination (24 or 60 h) changed the patterns for esterases, peroxidases and amylases, but not for phosphorylases. The charge distribution of proteins was markedly changed in the basic region. Roasting did not affect the distribution in standard PAGE. All bands in the basic region of PAGIF disappeared. High MW-proteins wre degraded to low MW-proteins as seen in SDS-PAGE. The cooking broth and the cooked beans of nabet soup and medammis had more or less similar patterns in the standard PAGE. The broth of nabet soup had larger number of low MW-proteins than the bean extract in SDS-PAGE. Bisara proteins showed almost the same patterns as the corresponding proteins of the cooking broth of nabet soup. Falafel proteins showed patterns very similar to that obtained from roasted beans in the SDS-PAGE. PAGIF gave a different but characteristic charge distribution for falafel. 相似文献
325.
Flora Mückschel Elijah Ollo Stefanie P. Glaeser Rolf Düring Feng Yan Hermann Velten Ulf Theilen Michael Frei 《植物养料与土壤学杂志》2023,186(5):522-531
Background
Wastewater from sewage treatment plants contains high levels of nutrients, which can be used for plant nutrition. Classical wastewater treatment plants use complex microbial consortia of autotrophic and heterotrophic microorganisms for biological wastewater treatment. Certain autotrophic microalgae (e.g., species of the genera Chlorella, Scenedesmus, and Pediastrum) accumulate nutrients from wastewater very effectively.Aims
We investigated the potential of microalgae biomass obtained from a prototype wastewater treatment plant as a source of nutrients for crops, focusing on nitrogen.Methods
We provided wheat plants with different levels of algae biomass equivalent to 60, 120, and 180 kg N per hectare or with mineral fertilizer (N, P, and K) equivalent to the amounts contained in the algal biomass. Physiological and phenotypic traits were measured during growth, including vegetation indices, photosynthetic performance, growth, and nitrogen use efficiency (NUE). In addition, the adundances of Bacteria, Archaea and fungi and genes of ammonium oxidizing Bacteria and Archaea were determined in the rhizosphere of differently fertilized plants.Results
Microalgal application at fertilizer levels of 120 and 180 kg N ha–1 showed significantly improved physiological performance, growth, yield and nutrient uptake compared to the unfertilized control. Nevertheless, their yields and NUE were lower than with the application of equal amounts of mineral fertilization, while the adundance of rhizosphere microbes and ammonia-oxidizing microorganisms were not significantly affected.Conclusions
Microalgae from wastewater treatments form a suitable source of organic fertilizer for wheat plants with only moderate reductions in N use efficiency compared to mineral fertilizer. 相似文献326.
Krzysztof Nowacki Maciej Galiski Andriy Fursov Alona Voronkina Heike Meissner Iaroslav Petrenko Allison L. Stelling Hermann Ehrlich 《Marine drugs》2022,20(11)
Three-dimensional chitinous scaffolds often used in regenerative medicine, tissue engineering, biomimetics and technology are mostly isolated from marine organisms, such as marine sponges (Porifera). In this work, we report the results of the electrochemical isolation of the ready to use chitinous matrices from three species of verongiid demosponges (Aplysina archeri, Ianthella basta and Suberea clavata) as a perfect example of possible morphological and chemical dimorphism in the case of the marine chitin sources. The electrolysis of concentrated Na2SO4 aqueous solution showed its superiority over the chemical chitin isolation method in terms of the treatment time reduction: only 5.5 h for A. archeri, 16.5 h for I. basta and 20 h for the S. clavata sample. Further investigation of the isolated scaffolds by digital microscopy and SEM showed that the electrolysis-supported isolation process obtains chitinous scaffolds with well-preserved spatial structure and it can be competitive to other alternative chitin isolation techniques that use external accelerating factors such as microwave irradiation or atmospheric plasma. Moreover, the infrared spectroscopy (ATR-FTIR) proved that with the applied electrochemical conditions, the transformation into chitosan does not take place. 相似文献