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Holliday CM, Sellers KC, Lessner EJ, Middleton KM, Cranor C, Verhulst CD, Lautenschlager S, Bader K, Brown MA, Colbert MW. New frontiers in imaging, anatomy, and mechanics of crocodylian jaw muscles. Anat Rec (Hoboken) 2022; 305:3016-3030. [PMID: 35723491 DOI: 10.1002/ar.25011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/16/2022] [Accepted: 05/21/2022] [Indexed: 12/12/2022]
Abstract
New imaging and biomechanical approaches have heralded a renaissance in our understanding of crocodylian anatomy. Here, we review a series of approaches in the preparation, imaging, and functional analysis of the jaw muscles of crocodylians. Iodine-contrast microCT approaches are enabling new insights into the anatomy of muscles, nerves, and other soft tissues of embryonic as well as adult specimens of alligators. These imaging data and other muscle modeling methods offer increased accuracy of muscle sizes and attachments without destructive methods like dissection. 3D modeling approaches and imaging data together now enable us to see and reconstruct 3D muscle architecture which then allows us to estimate 3D muscle resultants, but also measurements of pennation in ways not seen before. These methods have already revealed new information on the ontogeny, diversity, and function of jaw muscles and the heads of alligators and other crocodylians. Such approaches will lead to enhanced and accurate analyses of form, function, and evolution of crocodylians, their fossil ancestors and vertebrates in general.
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Affiliation(s)
- Casey M Holliday
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
| | - Kaleb C Sellers
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
| | - Emily J Lessner
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
| | - Kevin M Middleton
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
| | - Corrine Cranor
- Department of Geology and Geologic Engineering, South Dakota School of Mines and Technology, Rapid City, South Dakota, USA
| | - Conner D Verhulst
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
| | - Stephan Lautenschlager
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Kenneth Bader
- Texas Vertebrate Paleontology Collection, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
| | - Matthew A Brown
- Texas Vertebrate Paleontology Collection, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
| | - Matthew W Colbert
- Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
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Cranor C. Precautionary information-generation in science and the law. Water Sci Technol 2005; 52:65-71. [PMID: 16304936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
An information-generation system should be part of precautionary approaches to protecting the public's health and the environment. Such a system would include inventories or surveys of health and the environment, monitoring of them, as well as scoping out or scouting for threats or other harmful things that could occur and providing sentinels to try to identify threats before they materialize. I, then, suggest some ways in which such strategies could be adopted in science and the law as part of a precautionary approach. Doing more to generate information in an anticipatory way will assist implementation of the precautionary principle and help remove some of the uncertainty in environmental and public health protections.
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Affiliation(s)
- C Cranor
- Department of Philosophy, University of California, Riverside 92507, USA.
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Hoover SM, Zeise L, Pease WS, Lee LE, Hennig MP, Weiss LB, Cranor C. Improving the regulation of carcinogens by expediting cancer potency estimation. Risk Anal 1995; 15:267-280. [PMID: 7597261 DOI: 10.1111/j.1539-6924.1995.tb00320.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The statutory language of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65; California Health and Safety Code 25249.5 et seq.) encourages rapid adoption of "no significant risk levels" (NSRLs), intakes associated with estimated cancer risks of no more than 1 in 100,000. Derivation of an NSRL for a carcinogen listed under Proposition 65 requires the development of a cancer potency value. This paper discusses the methodology for the derivation of cancer potencies using an expedited procedure, and provides potency estimates for a number of agents listed as carcinogens under Proposition 65. To derive expedited potency values, default risk assessment methods are applied to data sets selected from an extensive tabulation of animal cancer bioassays according to criteria used by regulatory agencies. A subset of these expedited values is compared to values previously developed by regulatory agencies using conventional quantitative risk assessment and found to be in good agreement. Specific regulatory activities which could be facilitated by adopting similar expedited procedures are identified.
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Affiliation(s)
- S M Hoover
- Reproductive and Cancer Hazard Assessment Section, California Environmental Protection Agency, Berkeley 94704, USA
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