624 research outputs found
Genetic Variation and Geographical Differentiation of \u3cem\u3eElymus nutans\u3c/em\u3e (Poaceae: Triticeae) from West China
Elymus nutans Griseb. is not only an important alpine forage grass, but also as a crucial gene pool for improving cereal crops. Understanding and maintaining the genetic diversity of the species are essential for both conservation strategy and breeding programs. However, little is known about its genetic and geographical differentiation patterns. E. nutans is a perennial, caespitose and allohexaploid (2n=6x=42) species that contains the St, H and Y genomes. It is native to temperate and tropical Asia, ranging from western and central Asia in the west to China and Mongolia in the east, from Russia in the north to India and the Himalayas areas in the south (Clayton et al. 2006). It is distributed in the north, northwest and southwest China, particularly in the Qinghai-Tibet Plateau. E. nutans is a valuable forage grass in the alpine regions that is resistant to cold, drought and pests, which can be used to improve cereal crops. In addition, it can play an important role in the restoration of disturbed grasslands and the establishment of artificial grasslands, especially at altitudes from 3,000 to 4,500 m (Chen and Jia 2000). During recent decades, its distribution has contracted because of over-exploitation, habitat destruction and fragmentation. Therefore, it is urgent to understand and monitor the genetic and geographical differentiation of wild germplams of E. nutans
Operational Risk Management in Financial Institutions
This paper aims to explore to what extent can improve the efficiency of internal control in financial organisations, and use Final Notices form FCA as the evidence
Commentary: Causal associations of gut microbiota and metabolites on sepsis: a two-sample Mendelian randomization study
Protocol selection for second-order consensus against disturbance
Noticing that both the absolute and relative velocity protocols can solve the
second-order consensus of multi-agent systems, this paper aims to investigate
which of the above two protocols has better anti-disturbance capability, in
which the anti-disturbance capability is measured by the L2 gain from the
disturbance to the consensus error. More specifically, by the orthogonal
transformation technique, the analytic expression of the L2 gain of the
second-order multi-agent system with absolute velocity protocol is firstly
derived, followed by the counterpart with relative velocity protocol. It is
shown that both the L2 gains for absolute and relative velocity protocols are
determined only by the minimum non-zero eigenvalue of Laplacian matrix and the
tunable gains of the state and velocity. Then, we establish the graph
conditions to tell which protocol has better anti-disturbance capability.
Moreover, we propose a two-step scheme to improve the anti-disturbance
capability of second-order multi-agent systems. Finally, simulations are given
to illustrate the effectiveness of our findings
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