John T. Beneski

Demography and migratory patterns of the eastern long-toed salamander, Ambystoma macrodactylum columbianum

The breeding migration of the eastern long-toed salamander, Ambystoma macrodactylum columbianum, was studied at a small pond in NW Idaho using a drift fence and pitfall traps. During the period of 27 Feb.-25 April 1983, 2030 adult salamanders (1054 males and 976 females) were intercepted at the drift fence. The timing of migratory events was influenced by a combination of environmental and biological factors: 95% of all migration occurred when the minimum air temperature was 0 C or greater and 78% of all migration occurred on days with measurable precipitation. The pattern of migratory movement was either continuous or episodic, depending on the prevailing pattern of air temperatures and precipitation. Female salamanders arrived at the breeding pond later than males and appeared to leave the pond soon after oviposition; male emigration began shortly thereafter. No preferred migration routes with respect to various measures of habitat quality (i.e., habitat type, relative soil moisture, or vegetation type) were evident. Individual salamanders, however, did tend to use the same habitat for immigration and emigration. Based on the computed sampling efficiency of the drift fence, population size was estimated at 3141 adult salamanders (1986 males and 1155 females) in a 1.7:1 male: female sex ratio.

Examination of the three-dimensional geometry of cetacean flukes using computed tomography scans: Hydrodynamic implications

The flukes of cetaceans function in the hydrodynamic generation of forces for thrust, stability, and maneuverability. The three‐dimensional geometry of flukes is associated with production of lift and drag. Data on fluke geometry were collected from 19 cetacean specimens representing eight odontocete genera (Delphinus, Globicephala, Grampus, Kogia, Lagenorhynchus, Phocoena, Stenella, Tursiops). Flukes were imaged as 1 mm thickness cross‐sections using X‐ray computer‐assisted tomography. Fluke shapes were characterized quantitatively by dimensions of the chord, maximum thickness, and position of maximum thickness from the leading edge. Sections were symmetrical about the chordline and had a rounded leading edge and highly tapered trailing edge. The thickness ratio (maximum thickness/chord) among species increased from insertion on the tailstock to a maximum at 20% of span and then decreasing steadily to the tip. Thickness ratio ranged from 0.139 to 0.232. These low values indicate reduced drag while moving at high speed. The position of maximum thickness from the leading edge remained constant over the fluke span at an average for all species of 0.285 chord. The displacement of the maximum thickness reduces the tendency of the flow to separate from the fluke surface, potentially affecting stall patterns. Similarly, the relatively large leading edge radius allows greater lift generation and delays stall. Computational analysis of fluke profiles at 50% of span showed that flukes were generally comparable or better for lift generation than engineered foils. Tursiops had the highest lift coefficients, which were superior to engineered foils by 12–19%. Variation in the structure of cetacean flukes reflects different hydrodynamic characteristics that could influence swimming performance. Anat Rec, 290:614–623, 2007.

Structure and function of the hyolingual system in Hynobius and its bearing on the evolution of prey capture in terrestrial salamanders

The Hynobiidae is generally regarded as the most phylogenetically basal and least derived extant family of terrestrial salamanders. As in the other families of terrestrial salamanders, prey capture in the Hynobiidae is accomplished by lingual prehension. In Hynobius, the prey capture system appears to be a mosaic of derived and primitive features. This, in conjunction with previous studies, suggests that the hyolingual systems of all families of terrestrial salamanders have evolved various degrees of specialization since the appearance of the common ancestral condition. We propose that the generalized feeding system for the extant terrestrial salamanders includes a hyolingual skeleton comprised of one basibranchial, one pair of radial or radial‐like structures, two pairs of ceratobranchials, two pairs of epibranchials, one pair of ceratohyals, and one urohyal arranged in a configuration similar to that of Hynobius; a simple, sac‐like secondary tongue pad; a lift and thrust system of tongue projection; a four‐part gape cycle; and a forward head and body surge. Modifications to this general plan, previously described for the disparate families, include various changes in the size, shape, and definition of the tongue pad, changes in the specific types of structures and configurations in the anterior hyolingual skeleton, secondary ossification in the posterior hyolingual skeleton, the appearance of various protrusion, projection, and flipping systems for tongue protraction, simplification of the kinematic gape profile, and loss of the forward head and body surge. The evolutionary trends in these modifications have provided a rich data set from which much phylogenetic information has been inferred.

Evolution and Bio-Inspired Design: Natural Limitations

Biomimetics is the incorporation of novel structures and mechanisms from nature into the design and function of engineered systems. Promotion of biomimicry has been justified on the basis that evolution has modified structures and functions in organisms to achieve optimal solutions and maximize performance. Such justifications reflect an incomplete understanding of evolution and constraints imposed on biology. Evolution is not a conscious or predictive process and does not drive toward perfection. Organisms are not optimal with regard to any one specific function. Where a biological feature will out-perform available technologies, these features can be targeted for assimilation into bio-inspired designs. For engineers and entrepreneurial investors interested in a biomimetic approach, an understanding of evolution and the limitations and constraints that have shaped biological organisms are necessary to avoid unsupportable and overzealous claims.

Teaching physiology online: successful use of case studies in a graduate course.

To address the need for greater flexibility in access to higher education, an online graduate course in physiology using case studies was developed and offered in summer 2012. Topics in both animal and human physiology were organized as modules that contained a case study with questions, a prerecorded online lecture, and three research journal articles. We followed best practices for teaching and learning in distance education, including the preparation of materials before the course starting date, a discussion board for responding to pre- and postcase discussion questions, and prompt reply to student queries. For exams, students generated their own questions based on new cases and developed their own case study for the final project. Although only 20% of students had previously taken an online course, all students stated that they would recommend this course to others. Postcase assessment indicated that students found the cases interesting, informative, and presented at the appropriate level. Most students said that the online course took them more time but that they learned more content and used the primary literature more than in a traditional class. Our results indicate that a well-organized physiology course using a case study format is a very effective model for online learning.

Abstract 111: Regulation of alcohol dehydrogenase 1B by DNA methylation and histone modification in epithelial breast cell lines

Homeostasis of normal breast epithelium requires maintenance of a gene expression profile that is, in part, dependent on DNA methylation and histone modification. Tumorgenesis is marked by a disturbance of this profile, as the bulk of the tumor genome is hypomethylated with the exception of tumor suppressor genes that are typically hypermethylated. The hypermethylation interacts with histone modifications to suppress gene expression. Our previous research demonstrated that alcohol dehydrogenase (ADH) isozymes are expressed in normal breast tissue and down-regulated in breast cancer. In this study, qRT-PCR analysis of RNA extracted from normal breast epithelium reveals that ADH1B accounts for 95.8% of total ADH isozyme expression. Expression of ADH1B in RNA extracts from breast tumor is significantly down-regulated to 5.4% of normal expression (p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 111. doi:10.1158/1538-7445.AM2011-111