132,290 research outputs found
Special Features -- Remembrances of Philip F. Cohen
No full textI first met Phil Cohen in 1958 when I attended the AALL Annual Meeting in Washington, D.C., just before commencing my first law library job as assistant librarian in the Rutgers University Law School Library. Changing careers after seven years of stressful law practice in lower Manhattan filled me with some trepidation and much uncertainty. Phil's warm, avuncular welcome to the profession was reassuring and calming. Our common interests—rare books and the Columbia Law School (where he had worked and I had attended law school) made for quick bonding. His easy manner and vast knowledge of both law librarianship and law publishing accelerated my learning process into those arcane but essential subjects. He persuaded me quickly that I was coming into a humane and fascinating field. He introduced me around and offered informal sketches of the many new personalities I met. His insights were later proved remarkably accurate by my own observations. Throughout my subsequent career, Phil Cohen remained a good friend, a reliable and discreet confidante, and a thoughtful sounding board for new ideas, crucial decisions, or just plain advice
On the local-indicability cohen–lyndon theorem
No full textFor a group H and a subset X of H, we let HX denote the set {hxh?1 | h ? H, x ? X}, and when X is a free-generating set of H, we say that the set HX is a Whitehead subset of H. For a group F and an element r of F, we say that r is Cohen–Lyndon aspherical in F if F{r} is a Whitehead subset of the subgroup of F that is generated by F{r}. In 1963, Cohen and Lyndon (D. E. Cohen and R. C. Lyndon, Free bases for normal subgroups of free groups, Trans. Amer. Math. Soc. 108 (1963), 526–537) independently showed that in each free group each non-trivial element is Cohen–Lyndon aspherical. Their proof used the celebrated induction method devised by Magnus in 1930 to study one-relator groups. In 1987, Edjvet and Howie (M. Edjvet and J. Howie, A Cohen–Lyndon theorem for free products of locally indicable groups, J. Pure Appl. Algebra 45 (1987), 41–44) showed that if A and B are locally indicable groups, then each cyclically reduced element of A*B that does not lie in A ? B is Cohen–Lyndon aspherical in A*B. Their proof used the original Cohen–Lyndon theorem. Using Bass–Serre theory, the original Cohen–Lyndon theorem and the Edjvet–Howie theorem, one can deduce the local-indicability Cohen–Lyndon theorem: if F is a locally indicable group and T is an F-tree with trivial edge stabilisers, then each element of F that fixes no vertex of T is Cohen–Lyndon aspherical in F. Conversely, by Bass–Serre theory, the original Cohen–Lyndon theorem and the Edjvet–Howie theorem are immediate consequences of the local-indicability Cohen–Lyndon theorem. In this paper we give a detailed review of a Bass–Serre theoretical form of Howie induction and arrange the arguments of Edjvet and Howie into a Howie-inductive proof of the local-indicability Cohen–Lyndon theorem that uses neither Magnus induction nor the original Cohen–Lyndon theorem. We conclude with a review of some standard applications of Cohen–Lyndon asphericit
Cohen, Geoffrey F, S-2538
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/377914Surname: COHEN
Given Name(s) or Initials: GEOFFREY F
Military Service Number or Last Known Location: S-2538
Missing, Wounded and Prisoner of War Enquiry Card Index Number: 351191728
Item: [2016.0049.10209] "Cohen, Geoffrey F, S-2538
Cohen, Geoffrey F, S-2538
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/377913Surname: COHEN
Given Name(s) or Initials: GEOFFREY F
Military Service Number or Last Known Location: S-2538
Missing, Wounded and Prisoner of War Enquiry Card Index Number: 342191727
Item: [2016.0049.10208] "Cohen, Geoffrey F, S-2538
The cohomology of the braid group and of with coefficients in a geometric representation
No full textThis article is a short version of a paper which addresses the cohomology of the third braid group and of with coefficients in geometric representations.We give precise statements of the results, some tools and some proofs, avoiding very technical computations here
A Hormogonium Regulating Locus, hrmUA, of the Cyanobacterium Nostoc punctiforme Strain ATCC 29133 and its Response to an Extract of a Symbiotic Plant Partner Anthoceros Punctatus
No full textPublished by American Phytopathological SocietyTransposon-generated mutant strain UCD 328 of Nostoc\ud
punctiforme strain ATCC 29133 has a phenotype of an increased\ud
sensitivity to a hormogonium-inducing factor exuded\ud
by a symbiotic plant partner, Anthoceros punctatus,\ud
and an initial increased hormogonium-dependent infection\ud
of the plant. Sequence analysis showed that the transposition\ud
site in strain UCD 328 lies within a 1,251-bp open\ud
reading frame (ORF), designated hrmA, that displays no\ud
significant similarity to known database sequences. A second,\ud
837-bp ORF (hrmU) ends 2 bp 5?? from the start of\ud
hrmA and has the signature sequences belonging to a family\ud
of NAD(P)H-dependent oxidoreductases. Strains having\ud
insertional mutations in hrmU or hrmA reproduce the\ud
strain UCD 328 phenotype. Transcriptional fusions of\ud
luxAB to hrmU or hrmA show an 8- to 10-fold peak increase\ud
in luciferase activity 13 to 20 h after the start of incubation\ud
in the presence of an aqueous extract of A.\ud
punctatus. A promoter induced by the extract was deduced\ud
to be between 2.0 to 3.4 kb from the translational start of\ud
hrmU. A multicopy plasmid that contains hrmUA within a\ud
6.2-kb fragment conferred an increased infection phenotype\ud
on wild-type N. punctiforme 29133. This plasmid and\ud
another plasmid containing 4.4 kb of DNA 5?? of the transposition\ud
site prevented extract-dependent induction of\ud
hrmA-luxAB transcription in strain UCD 328, implicating\ud
titration of some trans-activator(s) by the cloned fragments.\ud
We hypothesize a role for hrmUA in the inhibition\ud
of hormogonium formation by the metabolism of an unknown\ud
hormogonium-regulating metabolite.This work was supported by the U. S. National\ud
Science Foundation (Grants IBN 92-06139 and IBN 95-14787) and a\ud
Floyd and Mary Schwall Fellowship in Medical Research to M. F. Cohen
Special Features -- Remembrances of Philip F. Cohen
No full textI first met Phil Cohen in 1958 when I attended the AALL Annual Meeting in Washington, D.C., just before commencing my first law library job as assistant librarian in the Rutgers University Law School Library. Changing careers after seven years of stressful law practice in lower Manhattan filled me with some trepidation and much uncertainty. Phil\u27s warm, avuncular welcome to the profession was reassuring and calming. Our common interests—rare books and the Columbia Law School (where he had worked and I had attended law school) made for quick bonding. His easy manner and vast knowledge of both law librarianship and law publishing accelerated my learning process into those arcane but essential subjects. He persuaded me quickly that I was coming into a humane and fascinating field. He introduced me around and offered informal sketches of the many new personalities I met. His insights were later proved remarkably accurate by my own observations. Throughout my subsequent career, Phil Cohen remained a good friend, a reliable and discreet confidante, and a thoughtful sounding board for new ideas, crucial decisions, or just plain advice
Oral History Interview with Dr. Edward Cohen
No full textEdward Hoddes Cohen joined the faculty of the English department in 1967 and has served Rollins College as an active academic and proactive force in the community.
Cohen was born on November 6, 1941, in Washington, District of Columbia. He studied at the University of Maryland, where he received his bachelor’s degree in English in 1963. In 1964, Cohen received his M.A. in English from the University of Iowa, and in 1967, he received his Ph.D. from the University of New Mexico.
Having joined the Rollins College faculty in 1967, Cohen has taught courses in English and also found time to publish articles and papers. He specializes in British and American Literature Since 1890 and is an expert of Victorian Literature. Over the years he has taught courses in topics such as Twentieth Century British Literature, British Romantics, and American Realism.
Throughout his Rollins career, Cohen has been recognized as an Arthur Vining Davis Fellow (1971), an Outstanding Educator in America (1971 and 1972), a Henry E. Huntington Library Fellow (1972), and an American Council on Education Fellow (1981). He participated in in the National Endowment for the Humanities Summer Seminar in 1977, received the Hugh F. McKean Honorary Award in 1979, and was awarded a National Humanities Center Fellowship in 1992.
In addition, Cohen was recognized as the William R. Kenan Jr. Professor of English. He has also served as a member of the Victorian Studies Bibliography Committee, the editor and compiler of the Victorian Bibliography, a member of the MLA Bibliography advisory committee, and a member of the Modern Language Association
Synergistic Effect of Deoxyanthocyanins from Symbiotic Fern Azolla spp. on hrmA Gene Induction in the Cyanobacterium Nostoc Punctiforme
No full textPublished by American Phytopathological SocietyThe hrmA gene of the N2-fixing cyanobacterium Nostoc punctiforme functions in repressing the formation of transitory motile filaments, termed hormogonia, by plant-associated vegetative filaments. Here, we report that anthocyanins can contribute to induction of hrmA expression. Aqueous extract from fronds of the fern Azolla pinnata, a host of symbiotic Nostoc spp., was found to be a potent inducer of hrmA-luxAB in N. punctiforme strain UCD 328. The hrmA-luxAB inducing activities of A. pinnata, as well as Azolla filiculoides, were positively correlated with levels of frond deoxyanthocyanins. Analyses of the deoxyanthocyanins in frond extracts revealed, in order of predominance, an acetylated glycoside derivative of luteolinidin (m/z 475) and of apigeninidin (m/z 459) and minor amounts of a second luteolinidin derivative. At up to 150 ??M, a purified preparation of deoxyanthocyanins only weakly induced hrmA-luxAB on its own, but mixtures with hrmA-luxAB inducers (A. filiculoides extract or the flavonoid naringin) synergistically doubled to tripled their inducing activities. These results suggest that appropriately localized deoxyanthocyanins could function in plant-mediated mechanisms for repressing Nostoc spp. hormogonium formation.Support to M. F. Cohen and Y. Sakihama were provided by fellowships from\ud
the Japanese Society for the Promotion of Science (JSPS). Funding was\ud
also provided to H. Yamasaki by Grant-in-Aid for Scientific Research on Priority\ud
Areas (C) Genome Science from the Ministry of Education, Science,\ud
Sports and Culture of Japan
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