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排序方式: 共有178条查询结果,搜索用时 31 毫秒
171.
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.
172.
Amegbor Isaac Kodzo Abe Ayodeji Adjebeng-Danquah Joseph Adu Gloria Baokyewaa Oteng-Frimpong Richard 《Journal of Crop Science and Biotechnology》2022,25(2):183-197
Journal of Crop Science and Biotechnology - Breeding for drought tolerance and increased grain yield is vital in mitigating the threat posed by recurrent drought stress on maize production, as well... 相似文献
173.
Guo Jianguo Oyediran Isaac Rice Marlin E. Brown Sebe Dimase Marcelo Lin Shucong Walker Wade Yu Wenbo Niu Ying Huang Fangneng 《Journal of pest science》2021,94(3):959-968
Journal of Pest Science - The Vip3A, a vegetative Bacillus thuringiensis (Bt) gene, has been introduced into many Cry maize and cotton varieties that can manage the recently occurred... 相似文献
174.
Hoffmeister KM Josefsson EC Isaac NA Clausen H Hartwig JH Stossel TP 《Science (New York, N.Y.)》2003,301(5639):1531-1534
Cooling of blood platelets clusters the von Willebrand factor receptor complex. Macrophage alphaMbeta2 integrins bind to the GPIbalpha subunit of the clustered complex, resulting in rapid clearance of transfused, cooled platelets. This precludes refrigeration of platelets for transfusion, but the current practice of room temperature storage has major drawbacks. We document that alphaMbeta2 is a lectin that recognizes exposed beta-N-acetylglucosamine residues of N-linked glycans on GPIbalpha. Enzymatic galactosylation of chilled platelets blocks alphaMbeta2 recognition, prolonging the circulation of functional cooled platelets. Platelet-associated galactosyltransferase produces efficient galactosylation when uridine diphosphate-galactose is added, affording a potentially simple method for storing platelets in the cold. 相似文献
175.
176.
Moyà-Solà S Köhler M Alba DM Casanovas-Vilar I Galindo J 《Science (New York, N.Y.)》2004,306(5700):1339-1344
We describe a partial skeleton with facial cranium of Pierolapithecus catalaunicus gen. et sp. nov., a new Middle Miocene (12.5 to 13 million years ago) ape from Barranc de Can Vila 1 (Barcelona, Spain). It is the first known individual of this age that combines well-preserved cranial, dental, and postcranial material. The thorax, lumbar region, and wrist provide evidence of modern ape-like orthograde body design, and the facial morphology includes the basic derived great ape features. The new skeleton reveals that early great apes retained primitive monkeylike characters associated with a derived body structure that permits upright postures of the trunk. Pierolapithecus, hence, does not fit the theoretical model that predicts that all characters shared by extant great apes were present in their last common ancestor, but instead points to a large amount of homoplasy in ape evolution. The overall pattern suggests that Pierolapithecus is probably close to the last common ancestor of great apes and humans. 相似文献
177.
Pathogenesis of spring viremia of carp virus in emerald shiner Notropis atherinoides Rafinesque,fathead minnow Pimephales promelas Rafinesque and white sucker Catostomus commersonii (Lacepede) 下载免费PDF全文
E Misk K Garver E Nagy S Isaac L Tubbs P Huber L Al‐Hussinee J S Lumsden 《Journal of fish diseases》2016,39(6):729-739
178.
Shulamit Manulis Isaac Ishaaya Albert S. Perry 《Pesticide biochemistry and physiology》1981,15(3):267-274
In apterous adults of the spirea aphid, Aphis citricola van der Goot, the optimum conditions for determining acetylcholinesterase (AChE) activity consist of reaction mixture of 0.1 M phosphate buffer (pH 7.5), 10?3M acetylthiocholine (ASCh), and enzyme extract equivalent to 80 ± 3 μg protein incubated for 15 min at 30°C. The Km value for ASCh (6.7 × 10?5M) was much lower than that of butyrylthiocholine (BuSCh) (1.25 × 10?2M). The enzyme activity was almost completely inhibited by 10?6M paraoxon or 10?5M eserine and was 84% inhibited by 10?5M BW284C51 (a specific AChE inhibitor). DTNB was found to inhibit the enzyme activity and was therefore added at the end of the reaction. AChE activity of A. citricola was inhibited in vitro and in vivo by dimethoxon > dimethoate, and aldicarb sulfoxide > aldicarb > aldicarb sulfone. The in vivo effect correlates well with the toxicity level of the various toxicants. A neurotoxicity index which combines both mortality and in vivo inhibition of the aphid AChE activity is suggested as a measure for determining the toxicity of organophosphorus and carbamate compounds toward aphids. 相似文献