2,111 research outputs found
Aspects of the curve complex and the mapping class group
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
An obstruction to the strong relative hyperbolicity of a group
No full textWe give a simple combinatorial criterion for a group that,
when satisfied, implies the group cannot be strongly relatively
hyperbolic. Our criterion applies to several classes of groups, such
as surface mapping class groups, Torelli groups, and automorphism
and outer automorphism groups of free groups
Free subgroups of surface mapping class groups
No full textWe quantify the generation of free subgroups of surface mapping class groups by pseudo-Anosov mapping classes in terms of their translation distance and the distance between their axes in Teichmueller's metric. The method makes reference to Teichmueller space only
Corrigendum to "free subgroups of surface mapping class groups"
No full textWe provide a corrigendum to the results of Conform. Geom. Dyn. 11 (2007), 44-55, pointing out an error in the proofs of Propositions 4.3 and 5.4 and providing corrected statements
Evolution of cooperation among tumor cells
No full textThe evolution of cooperation has a well established theoretical framework based on game theory. This approach has made valuable contributions to a wide variety of disciplines, including political science, economics, and evolutionary biology. Existing cancer theory suggests that individual clones of cancer cells evolve independently from one another, acquiring all of the genetic traits or hallmarks necessary to form a malignant tumor. It is also now recognized that tumors are heterotypic, with cancer cells interacting with normal stromal cells within the issue microenvironment, including endothelial, stromal, and nerve cells. This tumor cell???stromal cell interaction in itself is a form of commensalism, because it has been demonstrated that these nonmalignant cells support and even enable tumor growth. Here, we add to this theory by regarding tumor cells as game players whose interactions help to determine their Darwinian fitness. We marshal evidence that tumor cells overcome certain host defenses by means of diffusible products. Our original contribution is to raise the possibility that two nearby cells can protect each other from a set of host defenses that neither could survive alone. Cooperation can evolve as byproduct mutualism among genetically diverse tumor cells. Our hypothesis supplements, but does not supplant, the traditional view of carcinogenesis in which one clonal population of cells develops all of the necessary genetic traits independently to form a tumor. Cooperation through the sharing of diffusible products raises new questions about tumorigenesis and has implications for understanding observed phenomena, designing new experiments, and developing new therapeutic approaches.Author manuscript. Published in final edited form as: Proc Natl Acad Sci U S A. 2006 September 5; 103(36): 13474-13479.The final published version of this article is located at: www.pnas.org/cgi/doi/10.1073/pnas.0606053103NIH U56 CA113004; to David E. AxelrodR.A. was supported by National Science Foundation (NSF) Grant SES-0240852. D.E.A. was supported by NSF Grant IIS-0312953, National Institutes of Health (NIH) Grant U56 CA113004, and New Jersey Commission on Cancer Research Grant 1076-CCR-SO. K.J.P. is an American Cancer Society Clinical Research Professor and is supported by NIH Grants CA69568, CA102872, and CA093900.NIH CA69568; to Kenneth J. PientaNIH CA102872; to Kenneth J. PientaNIH CA093900; to Kenneth J. PientaNSF SES-0240852; to Robert AxelrodNJ Commission on Cancer Research 1076-CCR-SO; to David E. AxelrodAlso available in PubMed Central. PMCID: PMC155738
Uniformly exponential growth and mapping class groups of surfaces
No full textWe show that the mapping class group (as well as closely related groups) of an orientable surface with finitely generated fundamental group has uniformly exponential growth. We further demonstrate the uniformly non-amenability of many of these groups
Early Cenozoic benthic foraminiferal isotopes from ODP Hole 171-1052B
No full textData include also Shackleton N.J. unpublished data (1999
Ground-water hydrology of the upper Klamath Basin, Oregon and California
No full textby Marshall W. Gannett, Kenneth E. Lite Jr., Jonathan L. La Marche, Bruce J. Fisher, and Danial J. Polette ; prepared in cooperation with the Oregon Water Resources Department.Title from PDF cover (viewed on April 22, 2020).Covers OCLC #1151627285 and OCLC #123900688.This archived document is maintained by the State Library of Oregon. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references.Mode of access: Internet from the State Library of Oregon U.S. Government Publications Collection.Text in English
Child Welfare Practice : A Conversation About Reality
No full textBy Kenneth J. Herrmann, College at Brockport faculty member.
The author\u27s fifty years of practice in social work and child welfare have resulted in this examination and critique of America\u27s treatment of childhood. This advances a radical approach to ensuring the needs of children, an approach based in social justice and human rights.https://digitalcommons.brockport.edu/bookshelf/1345/thumbnail.jp
Life and experiences of George Washington Nichols
No full textTypescript of an account of some anecdotes from the life of George Washington Nichols (born 1859) of Salt Lake City. Author unknown; transcribed by Kenneth L. Seifert of Brigham City, April 25, 193
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