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Full-Text Articles in Physical Sciences and Mathematics

Betting & Hierarchy In Paleontology, Leonard Finkelman Jan 2019

Betting & Hierarchy In Paleontology, Leonard Finkelman

Faculty Publications

In his Rock, Bone, and Ruin: An Optimist’s Guide to the Historical Sciences, Adrian Currie argues that historical scientists should be optimistic about success in reconstructing the past on the basis of future research. This optimism follows in part from examples of success in paleontology. I argue that paleontologists’ success in these cases is underwritten by the hierarchical nature of biological information: extinct organisms have extant analogues at various levels of taxonomic, ecological, and physiological hierarchies, and paleontologists are adept at exploiting analogies within one informational hierarchy to infer information in another. On this account, fossils serve the role …


Interaction Of Fish Aryl Hydrocarbon Receptor Paralogs (Ahr1 And Ahr2) With The Retinoblastoma Protein, Rebeka R. Merson, Sibel I. Karchner, Mark E. Hahn Aug 2009

Interaction Of Fish Aryl Hydrocarbon Receptor Paralogs (Ahr1 And Ahr2) With The Retinoblastoma Protein, Rebeka R. Merson, Sibel I. Karchner, Mark E. Hahn

Faculty Publications

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) and related compounds. In some mammalian cell lines, TCDD induces G1 cell cycle arrest, which depends on an interaction between the AHR and the retinoblastoma tumor suppressor (RB). Mammals possess one AHR, whereas fishes possess two or more AHR paralogs that differ in the domains important for AHR-RB interactions in mammals. To test the hypothesis that fish AHR paralogs differ in their ability to interact with RB, we cloned RB cDNA from Atlantic killifish, Fundulus heteroclitus, and studied the interactions of killifish RB protein with killifish AHR1 and …


Association Between Fire Return Interval And Population Dynamics In Four California Populations Of Tecate Cypress (Cupressus Forbesii), Roland C. De Gouvenain, Ali M. Ansary Dec 2006

Association Between Fire Return Interval And Population Dynamics In Four California Populations Of Tecate Cypress (Cupressus Forbesii), Roland C. De Gouvenain, Ali M. Ansary

Faculty Publications

The Tecate cypress (Cupressus forbesii) is a tree species associated with chaparral ecosystems in southern California and northern Baja California, Mexico. It is fire-adapted, its regeneration triggered by the opening of serotinous cones when adult trees are burned. Surveys made in the 1980s by others suggested that some Tecate cypress populations were declining, and some authors suggested that increased fire frequency in southern California was a major factor for this decline. We asked whether current population trends were still negative for Tecate cypress 20 years later, and whether population growth was associated with fire return interval length. Based on demographic, …