Background: Circus cyaneus is a medium-sized bird of prey that is widely distributed across the Northern Hemisphere. There are two currently recognized forms, the Palearctic form C. c. cyaneus(Hen Harrier), and the Ne...Background: Circus cyaneus is a medium-sized bird of prey that is widely distributed across the Northern Hemisphere. There are two currently recognized forms, the Palearctic form C. c. cyaneus(Hen Harrier), and the Nearctic form C. c. hudsonius(Northern Harrier). The forms have recently been split by the British Ornithologists' Union but the American Ornithologists' Union and some other taxonomic committees have not yet made any change. Here we examine the phylogenetic relationship between the two forms using sequence data from multiple nuclear and mitochondrial genes and examine breeding biology, body size, morphology, dispersal and other behaviors.Methods: In order to fully compare cyaneus and hudsonius, we carried out a full literature review, measured museum skins and carried out phylogenetic analysis using a number of different mitochondrial genes and compare our findings to other recent work.Results: We find that these two allopatric taxa form reciprocally monophyletic groups, show substantial mt DNA sequence divergence, and further differ significantly with respect to body size, plumage characters, breeding biology, dispersal and other behavioral traits.Conclusions: Based on an array of consistently divergent characteristics, it is suggested that the two forms are best regarded as separate species, Hen Harrier(Circus cyaneus) and Northern Harrier(Circus hudsonius).展开更多
WHEN most people think of unicycles, they think about acrobats at the circus. But today unicycles are appearing everywhere, ridden by everyday people. Since the 1940s more and more of these one wheeled cycles have mad...WHEN most people think of unicycles, they think about acrobats at the circus. But today unicycles are appearing everywhere, ridden by everyday people. Since the 1940s more and more of these one wheeled cycles have made the crossover from stage to sports ground. It has become popular in more than 200 countries and regions. In the early 1980s, the World Unicycle Union was established and people from 220 countries and regions became members. Six展开更多
The thirty years“Golden Clown”It is rare for any event to capture the imagination of an entire population but the whole of Monaco seemed to be in the grip of circus fever for the 30th International Monte Carlo Circu...The thirty years“Golden Clown”It is rare for any event to capture the imagination of an entire population but the whole of Monaco seemed to be in the grip of circus fever for the 30th International Monte Carlo Circus Festival.展开更多
Desiderius Erasmus?"Copia"is not only inscribed with rhetorical interpretations but also implied with semiotic meanings.This paper starts from the definition,components,and functions of"Copia"and t...Desiderius Erasmus?"Copia"is not only inscribed with rhetorical interpretations but also implied with semiotic meanings.This paper starts from the definition,components,and functions of"Copia"and then analyzes Nights at the Circus from two aspects:the abundance of expression and the abundance of subject-matter,through discussing the employment of metaphor and antonomasia,the dividing of a whole into parts,and the tracing of causes in this novel.This research finds that the use of"Copia"can not only contribute to the richness and variety of style but also highlight the characters?personalities and enable Angela Carter to discuss political and social issues such as patriarchy and individual rights.From a perspective of Bakhtin's cultural semiotics,the paper aims to explore"Copia"semiotic meanings in literary classics and provide alternative interpretations of this conception in literary criticism.展开更多
基金The costs for the Cytochrome b sequencing and sample procurement was provided by the Museum of Vertebrate Zoology,UC Berkeley.Transport costs for museum visits were met by GJE
文摘Background: Circus cyaneus is a medium-sized bird of prey that is widely distributed across the Northern Hemisphere. There are two currently recognized forms, the Palearctic form C. c. cyaneus(Hen Harrier), and the Nearctic form C. c. hudsonius(Northern Harrier). The forms have recently been split by the British Ornithologists' Union but the American Ornithologists' Union and some other taxonomic committees have not yet made any change. Here we examine the phylogenetic relationship between the two forms using sequence data from multiple nuclear and mitochondrial genes and examine breeding biology, body size, morphology, dispersal and other behaviors.Methods: In order to fully compare cyaneus and hudsonius, we carried out a full literature review, measured museum skins and carried out phylogenetic analysis using a number of different mitochondrial genes and compare our findings to other recent work.Results: We find that these two allopatric taxa form reciprocally monophyletic groups, show substantial mt DNA sequence divergence, and further differ significantly with respect to body size, plumage characters, breeding biology, dispersal and other behavioral traits.Conclusions: Based on an array of consistently divergent characteristics, it is suggested that the two forms are best regarded as separate species, Hen Harrier(Circus cyaneus) and Northern Harrier(Circus hudsonius).
文摘WHEN most people think of unicycles, they think about acrobats at the circus. But today unicycles are appearing everywhere, ridden by everyday people. Since the 1940s more and more of these one wheeled cycles have made the crossover from stage to sports ground. It has become popular in more than 200 countries and regions. In the early 1980s, the World Unicycle Union was established and people from 220 countries and regions became members. Six
文摘The thirty years“Golden Clown”It is rare for any event to capture the imagination of an entire population but the whole of Monaco seemed to be in the grip of circus fever for the 30th International Monte Carlo Circus Festival.
文摘Desiderius Erasmus?"Copia"is not only inscribed with rhetorical interpretations but also implied with semiotic meanings.This paper starts from the definition,components,and functions of"Copia"and then analyzes Nights at the Circus from two aspects:the abundance of expression and the abundance of subject-matter,through discussing the employment of metaphor and antonomasia,the dividing of a whole into parts,and the tracing of causes in this novel.This research finds that the use of"Copia"can not only contribute to the richness and variety of style but also highlight the characters?personalities and enable Angela Carter to discuss political and social issues such as patriarchy and individual rights.From a perspective of Bakhtin's cultural semiotics,the paper aims to explore"Copia"semiotic meanings in literary classics and provide alternative interpretations of this conception in literary criticism.
