Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most stud...Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the biology and genetics of the invader. We investigated the invasion of Lord Howe Island by the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture （whether new haplotypes had been introduced to the island, and shifts in haplotype frequencies） of the species on the island between these two time points. No new haplotypes were introduced to the island between 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enable us to better manage their impacts展开更多
Let W be a real symplectic space and(G,G')an irreducible dual pair in Sp(W),in the sense of Howe,with G compact.Let G be the preimage of G in the metaplectic group Sp(W).Given an irreducible unitary representation...Let W be a real symplectic space and(G,G')an irreducible dual pair in Sp(W),in the sense of Howe,with G compact.Let G be the preimage of G in the metaplectic group Sp(W).Given an irreducible unitary representation II of G that occurs in the restriction of the Weil representation to G,let On denote its character.We prove that,for a suitable embedding T of Sp(W)in the space of tempered distributions on W,the distribution T(On)admits an asymptotic limit,and the limit is a nilpotent orbital integral.As an application,we compute the wave front set of II',the representation of G dual to II,by elementary means.展开更多
Why the particular emphasis proposed in my title on Shakespeare’s importance for experimental or avant-garde American poetry?We can take Shakespeare’s significance for American poetry generally,as for most writers i...Why the particular emphasis proposed in my title on Shakespeare’s importance for experimental or avant-garde American poetry?We can take Shakespeare’s significance for American poetry generally,as for most writers in the English language,as a given.One can certainly trace Shakespeare’s presence in a wide range of more mainstream twentieth-century poetry,from John Berryman to Anthony Hecht to Sylvia Plath,and anthologies of poetic responses to Shakespeare abound.But the use of the ultimate canonical Anglophone writer by experimental poets dedicated to changing the context of writing and reception in their own time raises some interesting questions not just about Shakespeare’s universal accessibility,availability,and usefulness but about later experimental poets’senses of rupture and continuity.I’m interested in Shakespeare less as a site of continuity and tradition and more one of productive conflict and difference,in what Shakespeare has meant for experimental American poets not just as writer but as symbolic figure,as one of Ralph Waldo Emerson’s“representative men.”My goal,then,is not merely to point to the multiple American poetic uses of Shakespeare,but more specifically to suggest how some American poets(from Emerson and Williams to such contemporaries as Susan Howe,Harryette Mullen,Jen Bervin,and K.Silem Mohammad)have used or identified with Shakespeare to buttress what is often a particularly American version of avant-garde poetics.展开更多
文摘Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the biology and genetics of the invader. We investigated the invasion of Lord Howe Island by the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture （whether new haplotypes had been introduced to the island, and shifts in haplotype frequencies） of the species on the island between these two time points. No new haplotypes were introduced to the island between 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enable us to better manage their impacts
基金the University of Oklahoma for hospitality and financial supporthospitality and financial support from the Université de Lorraine+1 种基金partial support from NSA (Grant No. H98230-13-1-0205)NSF (Grant No. DMS-2225892)
文摘Let W be a real symplectic space and(G,G')an irreducible dual pair in Sp(W),in the sense of Howe,with G compact.Let G be the preimage of G in the metaplectic group Sp(W).Given an irreducible unitary representation II of G that occurs in the restriction of the Weil representation to G,let On denote its character.We prove that,for a suitable embedding T of Sp(W)in the space of tempered distributions on W,the distribution T(On)admits an asymptotic limit,and the limit is a nilpotent orbital integral.As an application,we compute the wave front set of II',the representation of G dual to II,by elementary means.
文摘Why the particular emphasis proposed in my title on Shakespeare’s importance for experimental or avant-garde American poetry?We can take Shakespeare’s significance for American poetry generally,as for most writers in the English language,as a given.One can certainly trace Shakespeare’s presence in a wide range of more mainstream twentieth-century poetry,from John Berryman to Anthony Hecht to Sylvia Plath,and anthologies of poetic responses to Shakespeare abound.But the use of the ultimate canonical Anglophone writer by experimental poets dedicated to changing the context of writing and reception in their own time raises some interesting questions not just about Shakespeare’s universal accessibility,availability,and usefulness but about later experimental poets’senses of rupture and continuity.I’m interested in Shakespeare less as a site of continuity and tradition and more one of productive conflict and difference,in what Shakespeare has meant for experimental American poets not just as writer but as symbolic figure,as one of Ralph Waldo Emerson’s“representative men.”My goal,then,is not merely to point to the multiple American poetic uses of Shakespeare,but more specifically to suggest how some American poets(from Emerson and Williams to such contemporaries as Susan Howe,Harryette Mullen,Jen Bervin,and K.Silem Mohammad)have used or identified with Shakespeare to buttress what is often a particularly American version of avant-garde poetics.
