13,506 research outputs found
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
Review of David J. Baker, On Demand: Writing for the Market in Early Modern England.
No full textDavid J. Baker, On Demand: Writing for the Market in Early Modern England. Stanford: Stanford University Press, 2010 199 pp (+xviii) ISBN 9780804738569
The Arts Interview. Dr. David Pitt : The Truant Years, E. J. Pratt
No full textHost Fred Hollingshurst interviews Dr. David Pitt of Memorial University, who discusses the life and work of Newfoundland poet E. J. Pratt. Pitt is the author of E. J. Pratt: The Truant Years, 1881-1927
David J. Baker, On Demand: Writing for the Market in Early Modern England. Stanford: Stanford University Press, 2010
No full textThe article reviews the book "On Demand: Writing for the Market in Early Modern England," by David J. Bake
Resource competition between genetically varied and genetically uniform populations of Daphnia pulex (Leydig): does sexual reproduction confer a short-term ecological advantage?
No full textSmall competitive advantages may suffice to compensate for a large disadvantage in intrinsic growth capacity. This well-known principle from ecology has recently been applied to the enduring question of how sexual reproduction can persist in the face of invasion by female-only parthenogens. Small competitive advantages resulting directly from sexual reproduction are predicted to cancel a two-fold disadvantage in intrinsic growth capacity caused by males (which do not themselves produce offspring) comprising half the sexual population. In this paper we test the principal assumption of this theory, that the genetic variation produced by sexual reproduction confers a competitive advantage over self-identical asexual invaders. We set up competition between a diverse clonal assembly of Daphnia pulex and genetically uniform populations from single clones. At young ages, the population comprising genetically varied Daphnia had significantly higher birth rates in competition with populations of genetically uniform Daphnia than in competition with itself, indicating competitive release and a Lotka-Volterra competition coefficient ?12 < 1. No such difference was apparent under conditions of greater food stress, possibly due to individuals channelling more energy into survival, or for old-aged populations, possibly as a result of reduced selective pressures for high reproduction in old females. Mean birth rates differed between the clones at all ages in the presence of competition, providing evidence of variation in life history traits between clones. A Lotka-Volterra model predicted empirical estimates of ?12 = 0.896 (genetically uniform on varied) and ?21 = 1.010 (varied on uniform), which permits immediate coexistence of a sexual population of D. pulex even with an asexual lineage having twice the intrinsic growth capacity
Analysis methods for measuring passive auditory fNIRS responses generated by a block-design paradigm
No full textData in BIDS format from:
Robert Luke, Eric D. Larson, Maureen J. Shader, Hamish Innes-Brown, Lindsey Van Yper, Adrian K. C. Lee, Paul F. Sowman, David McAlpine, "Analysis methods for measuring passive auditory fNIRS responses generated by a block-design paradigm," Neurophoton. 8(2) 025008 (22 May 2021) https://doi.org/10.1117/1.NPh.8.2.02500
Fly about round me coursing, swallow sweet birds come near [first line]
No full textstrophicpiano and voiceCover is duplicated in 125.115b.Johns Hopkins University, Levy Sheet Music Collection, Box
125, Item 115aTranslated From the French of Volney L'Hotelier by Samuel J. Gardner, Esq. The Music by Felicien David (Author of "Le Desert").E.G. Warren, Engr
Fly about round me coursing, swallow sweet birds come near [first line]
No full textstrophicpiano and voiceCover is duplicated in 125.115b.Johns Hopkins University, Levy Sheet Music Collection, Box
125, Item 115aTranslated From the French of Volney L'Hotelier by Samuel J. Gardner, Esq. The Music by Felicien David (Author of "Le Desert").E.G. Warren, Engr
Interview with David Dunn on the subject of bark beetle sounds
No full textAnimaliaArthropodaInsectaColeopteraCompressed from .wav format into .mp3 delivery formatComposer and recording engineer David Dunn describes his recordings of bark beetles in New Mexico, and some of the possible causes and consequences of bark beetle infestations devastating pine forests throughout the WestSounds were recorded using a modified transducer inserted into the bark of the tree, and are taken with permission of the author from the compact disc "The Sound of Light in Trees" produced by David Dunn in collaboration with the Acoustic Ecology Institute. Scientists say that bark beetle populations are increasing in large part because of increased drought and milder winters due to global warming
The invisible artist: Arrangers in popular music (1950-2000): Their contribution and techniques
No full textThis thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.This thesis is based on the research conducted by the author for the series,
Richard Niles' History of Pop Arranging, seven thirty-minute documentary
programmes for BBC Radio 2, researched, written and presented by the author and
broadcast in 2003. It also draws on interviews conducted by the author (and other
research) between 2002 and 2007 both for the radio series and for this thesis and on
the author's experience as a professional arranger in popular music working with
many of the genre's significant recording artists including Paul McCartney, Ray
Charles, Cher, Tina Turner, Westlife, Tears For Fears, Dusty Springfield, James
Brown, Pet Shop Boys, Kylie Minogue and producers including Trevor Hom, Steve
Lipson, Steve Mac and Steve Anderson.
It will be argued that the role of the arranger in popular music has often been
undervalued and that during a critical period of popular music history (1950-2000)
arrangers played a significant part in the evolution of musical content. This thesis is,
to the best of the author's knowledge, the first time (apart from the above mentioned
documentary) the subject has ever been examined. The arranger is "invisible" because musical arrangers are often un-credited on
record liner notes or in books or articles concerning popular music. A considerable
amount of research has been necessary to determine who wrote many of the
arrangements considered herein. Motown's Berry Gordy purposely kept the names of
musicians and arrangers off the records because he feared others might 'poach' the
trademark 'Motown Sound'. Other record labels considered the job of the arranger to
be reminiscent of an earlier era, diluting the Rock 'n' Roll image of emotion and
spontanaeity they wished to promote. Some producers and recording artists disliked
sharing credit for their work. Motown arranger David Van dePitte told the author that
arranging was "thankless and anonymous - a very service-oriented profession where
others often take credit for what you've done." Arranging has therefore remained an
intrinsically unseen art created by 'invisible' artists. By analyzing many recordings,
revealing the techniques and concepts they have used in their work to create popular
records, arrangers and their art will be made more 'visible'
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