Search

Your search keyword '"Kennard, O"' showing total 249 results
Start Over Author "Kennard, O"
249 results on '"Kennard, O"'

123. Powder Data

Author

Kennard, O., primary, Hanawalt, J. D., additional, Wilson, A. J. C., additional, de Wolff, P. M., additional, and Frank-Kamenetsky, V. A., additional

Published
1971
Full Text
View/download PDF

133. The structure of abieslactone

Author

Kutney, James P., primary, D. Westcott, Neil, additional, Allen, F.H., additional, Isaacs, N.W., additional, Kennard, O., additional, and Motherwell, W.D.S., additional

Published
1971
Full Text
View/download PDF

135. Porphin

Author

Rimington, C., primary, Mason, S.F., additional, and Kennard, O., additional

Published
1958
Full Text
View/download PDF

141. Base-Pair Mismatch in DNA at 2.3A Resolution

Author

Brown, T, Kennard, O, Kneale, G, and Rabinovich, D

Subjects
chemistry.chemical_compound, Crystallography, Base Pair Mismatch, Speed wobble, chemistry, Stereochemistry, Fragment (computer graphics), Resolution (electron density), Genetics, Biochemistry, Single crystal, DNA
Abstract

X-ray single crystal analysis of the deoxyoctanucleotide d(GGGGCTCC)2 has revealed, for the first time, the existence of the G.T wobble mispair in an A-DNA double helical fragment.

Published
1985
Full Text
View/download PDF

142. President's page: Merle Tuve: A golden anniversary

Author

Kennard O. Whitfield

Subjects
Higher education, Nothing, business.industry, media_common.quotation_subject, Technician, General Earth and Planetary Sciences, Gender studies, Mexican americans, business, Racism, media_common
Abstract

In the long history of American racial discrimination, American blacks, Mexican Americans, Puerto Ricans, and American Indians frequently were denied basic educational opportunities, to say nothing of college and graduate training. As a result, they are still severely underrepresented at the undergraduate and graduate levels of American higher education. The need for the appearance of minorities among geophysical scientists has been apparent for a long time. The absence of significant participation by minorities in geology, seismology, hydrology, meteorology, oceanography, and the other disciplines of the geophysical sciences represents a loss of creative energy at both the professional and the technician level.

Published
1976
Full Text
View/download PDF

143. The President's Page: Increasing minority participation in the geophysical sciences [Guest Editorial]

Author

Kennard O. Whitfield

Subjects
Leverage (negotiation), Spanish surname, Political science, Professional development, Critical question, Ethnic group, General Earth and Planetary Sciences, Professional association, Geophysics, Indigenous
Abstract

Perhaps the most ignored yet among the most vital resources in the community are the indigenous talents of members of the ethnic minority groups (black Americans, Spanish surname Americans, Indian Americans) and women. Today only a very limited number of persons from these groups have the professional training and experience to assume professional leadership in the geophysical sciences and related fields. This fact presents community leaders, educational institutions, and professional societies with a crucial problem-how to develop and utilize the skills of a larger corps of minority specialists in the geophysical professions. Hence the critical question that faces the AGU Committee on Minorities is How can the American Geophysical Union use its resources, most of which are intellectual, with the greatest leverage to increase minority participation in the geophysical sciences both in the short term and over the next generation?

Published
1974
Full Text
View/download PDF

148. The bi-loop, a new general four-stranded DNA motif.

Author

Salisbury SA, Wilson SE, Powell HR, Kennard O, Lubini P, Sheldrick GM, Escaja N, Alazzouzi E, Grandas A, and Pedroso E

Subjects
Base Composition, Base Sequence, Crystallization, Crystallography, X-Ray, Cytosine, Guanine, Hydrogen Bonding, Models, Genetic, Models, Molecular, Molecular Sequence Data, Oligodeoxyribonucleotides chemical synthesis, DNA chemistry, Nucleic Acid Conformation, Oligodeoxyribonucleotides chemistry
Abstract

The crystal structure of the cyclic octanucleotide d contains two independent molecules that form a novel quadruplex by means of intermolecular Watson-Crick A.T pairs and base stacking. A virtually identical quadruplex composed of G.C pairs was found by earlier x-ray analysis of the linear heptamer d(GCATGCT), when the DNA was looped in the crystal. The close correspondence between these two structures of markedly dissimilar oligonucleotides suggests that they are both examples of a previously unrecognized motif. Their nucleotide sequences have little in common except for two separated 5'-purine-pyrimidine dinucleotides forming the quadruplex, and by implication these so-called "bi-loops" could occur widely in natural DNA. Such structures provide a mechanism for noncovalent linking of polynucleotides in vivo. Their capacity to associate by base stacking, demonstrated in the crystal structure of d(GCATGCT), creates a compact molecular framework made up of four DNA chains within which strand exchange could take place.

Published
1997
Full Text
View/download PDF

149. Parallel and antiparallel (G.GC)2 triple helix fragments in a crystal structure.

Author

Vlieghe D, Van Meervelt L, Dautant A, Gallois B, Précigoux G, and Kennard O

Subjects
Base Composition, Base Sequence, Crystallography, X-Ray, Hydrogen Bonding, Models, Molecular, Molecular Sequence Data, DNA chemistry, Nucleic Acid Conformation, Oligodeoxyribonucleotides chemistry
Abstract

Nucleic acid triplexes are formed by sequence-specific interactions between single-stranded polynucleotides and the double helix. These triplexes are implicated in genetic recombination in vivo and have application to areas that include genome analysis and antigene therapy. Despite the importance of the triple helix, only limited high-resolution structural information is available. The x-ray crystal structure of the oligonucleotide d(GGCCAATTGG) is described; it was designed to contain the d(G middle dotGC)2 fragment and thus provide the basic repeat unit of a DNA triple helix. Parameters derived from this crystal structure have made it possible to construct models of both parallel and antiparallel triple helices.

Published
1996
Full Text
View/download PDF

150. High-resolution structure of a DNA helix forming (C.G)*G base triplets.

Author

Van Meervelt L, Vlieghe D, Dautant A, Gallois B, Précigoux G, and Kennard O

Subjects
Base Sequence, Crystallography, X-Ray, Hydrogen Bonding, Models, Molecular, Molecular Sequence Data, Nucleic Acid Conformation, Oligodeoxyribonucleotides chemistry
Abstract

Triple helices result from interaction between single- and double-stranded nucleic acids. Their formation is a possible mechanism for recombination of homologous gene sequences in nature and provides, inter alia, a basis for artificial control of gene activity. Triple-helix motifs have been extensively studied by a variety of techniques, but few high-resolution structural data are available. The only triplet structures characterized so far by X-ray diffraction were in protein-DNA complexes studied at about 3 A resolution. We report here the X-ray analysis of a DNA nonamer, d(GCGAATTCG), to a resolution of 2.05 A, in which the extended crystal structure contains (C.G)*G triplets as a fragment of triple helix. The guanosine-containing chains are in a parallel orientation. This arrangement is a necessary feature of models for homologous recombination which results ultimately in replacement of one length of DNA by another of similar sequence. The present-structure agrees with many published predictions of triplex organization, and provides an accurate representation of an element that allows sequence-specific association between single- and double-stranded nucleic acids.

Published
1995
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results