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Radford, VA, United States

Gruss L.T.,Radford University | Schmitt D.,Duke University
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2015

The fossil record of the human pelvis reveals the selective priorities acting on hominin anatomy at different points in our evolutionary history, during which mechanical requirements for locomotion, childbirth and thermoregulation often conflicted. In our earliest upright ancestors, fundamental alterations of the pelvis compared with non-human primates facilitated bipedal walking. Further changes early in hominin evolution produced a platypelloid birth canal in a pelvis that was wide overall, with flaring ilia. This pelvic form was maintained over 3–4 Myr with only moderate changes in response to greater habitat diversity, changes in locomotor behaviour and increases in brain size. It was not until Homo sapiens evolved in Africa and the Middle East 200 000 years ago that the narrow anatomically modern pelvis with a more circular birth canal emerged. This major change appears to reflect selective pressures for further increases in neonatal brain size and for a narrow body shape associated with heat dissipation in warm environments. The advent of the modern birth canal, the shape and alignment of which require fetal rotation during birth, allowed the earliest members of our species to deal obstetrically with increases in encephalization while maintaining a narrow body to meet thermoregulatory demands and enhance locomotor performance. © 2015 The Author(s) Published by the Royal Society. All rights reserved. Source


Schirr G.R.,Radford University
Journal of Product Innovation Management | Year: 2012

Group customer and user research methods, brainstorming, and focus groups continue to be used in innovation efforts to uncover customer needs, generate new product and service ideas, and evaluate decisions, despite extensive empirical evidence that group methods are ineffective for such purposes. This paper summarizes the strong evidence of the ineffectiveness of group research methods for these purposes, much of which has been published outside of the new product development or business literature. The paper shows that the most common rationalization for the continued use of group methods-cost and speed advantages-are questionable, and then proposes an organizational market learning framework for evaluating the use of group methods. This framework provides guidance for the proper use of these research tools and suggests areas for future research on research methods for product innovation. © 2012 Product Development & Management Association. Source


Dunleavy M.,Radford University
TechTrends | Year: 2014

Augmented reality is an emerging technology that utilizes mobile, context-aware devices (e.g., smartphones, tablets) that enable participants to interact with digital information embedded within the physical environment. This overview of design principles focuses on specific strategies that instructional designers can use to develop AR learning experiences. A review of the literature reveals the following three design principles as instructive: 1. Enable and then challenge (challenge): 2. Drive by gamified story (fantasy); and 3. See the unseen (curiosity). These design principles can also be viewed as an attempt to either leverage the unique affor- dances of AR or minimize the limitations of the medium as reported in the literature (Dunleavy & Dede, 2014). As the field matures and more research teams explore the potential of AR to enhance teaching and learning, it will be critical to determine the design techniques that optimize the unique affordances of AR, minimize the limitations of the medium, and ultimately enhance learning across the curriculum. © 2013 Association for Educational Communications and Technology. Source


Belden L.K.,Virginia Polytechnic Institute and State University | Wojdak J.M.,Radford University
Oecologia | Year: 2011

Predators can have important impacts on host-parasite dynamics. For many directly transmitted parasites, predators can reduce transmission by removing the most heavily infected individuals from the population. Less is known about how predators might influence parasite dynamics in systems where the parasite relies on vectors or multiple host species to complete their life cycles. Digenetic trematodes are parasitic flatworms with complex life cycles typically involving three host species. They are common parasites in freshwater systems containing aquatic snails, which serve as obligate first intermediate hosts, and multiple trematode species use amphibians as second intermediate hosts. We experimentally examined the impact of predatory salamanders (Ambystoma jeffersonianum) and trematode parasites (Echinostoma trivolvis and Ribeiroia ondatrae) on short-term survival of wood frog tadpoles (Rana sylvatica) in 150-L outdoor pools. Two trematode species were used in experiments because field surveys indicated the presence of both species at our primary study site. Parasites and predators both significantly reduced tadpole survival in outdoor pools; after 6 days, tadpole survival was reduced from 100% in control pools to a mean of 46% in pools containing just parasites and a mean of 49% in pools containing just predators. In pools containing both infected snails and predators, tadpole survival was further reduced to a mean of 5%, a clear risk-enhancement or synergism. These dramatic results suggest that predators may alter transmission dynamics of trematodes in natural systems, and that a complete understanding of host-parasite interactions requires studying these interactions within the ecological framework of community interactions. © 2011 Springer-Verlag. Source


Ellis S.C.,University of Kentucky | Shockley J.,Radford University | Henry R.M.,Cleveland State University
Journal of Supply Chain Management | Year: 2011

The rich stream of supply disruption risk (SDR) literature incorporates several different theories and constructs across studies, but lacks a unifying decision-making framework. We review 79 SDR studies and advance a comprehensive framework, grounded in enactment theory, which integrates the disparate elements of SDR research and offers new insights into the SDR decision-making process. Enactment theory posits a three-stage, closed-loop process, consisting of enactment, selection and retention, through which individuals process and make sense of equivocal environments. We suggest that this sense-making process also underlies SDR decision-making, and provides the theoretical underpinnings for the environmental, organizational and individual factors that affect the formation of buyers' perceptions of SDR and the actions they take to mitigate such risks. In accordance with our conceptual framework, we develop seven propositions that advance the social and psychological factors that drive the idiosyncratic nature of SDR decision-making. © 2011 Institute for Supply Management, Inc.™. Source

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