3-D IMAGING AND ANIMATION APPLIED TO FOOT STRUCTURES IN WALKING AND RUNNING : PHASE TWO : SOFT TISSUES AND USER INTERFACE*

In order to counteract learning and training difficulties encountered by physical education students, coaches and athletes, due to poor or inadequate 3-D visual representation of human body structures and movements, a low cost computer platform capable of 3-D objects generation and animation has been developed. The first phase of the project (presented at ISBS '93) was dealing with 3-D imaging and animation of bone structures of the foot in walking. The second phase of the study was pursuing three main objectives : 1) generation of 3-D representations of the soft tissues of the foot, 2) 3-D animation of the bone structures of the foot in running, and 3) development of a user interface easily accessible with the mouse or the keyboard. The final product enables the user to have access to the following 3-D illustrations : 1) multiple views of the bony structures of the lower leg and foot, 2) multiple views of the ankle and foot ligaments and fascia, 3) multiple views of the muscles and tendons involved in ankle and foot movements, 4) multiple views of lower leg and foot articular surfaces, 5) identification of individual foot structures. The user can also select to view any of the following movement sequences : 1) talus-calcaneum joint movement animation, 2) animation of lower leg and foot structures in walking (side view or rear view) together with a reference manikin and a time code, 3) animation of lower leg and foot structures in running (side view or rear view) together with a reference manikin and a time code. Comparative evaluation of teaching structural kinesiology, biomechanics and sport traumatology courses with and without the use of this tool has demonstrated that retention can be increased with this computer-assisted technique. *Research supported with funds from the Pedagogic Innovation Program of the University of Sherbrooke

3-D Imaging Applied To Foot Structures In Walking

Pedagogic and coaching experiments have demonstrated that learning and training difficulties encountered by physical education students, athletes and coaches are frequently related to poor or inadequate 3-D visual representation of human body structures and movement. In order to counteract this important shortcoming, a low cost computer platform including an Amiga 3000T computer, preparation software (Imagine and DCTV) and presentation software, has been developed. The purpose of this study was to generate 3-D objects of the ankle-foot structures and to animate these objects in order to accurately illustrate plantar flexion, dorsiflexion, supination and pronation of the foot as a function of the walking cycle. Using anatomical and biomechanical informations available in literature, this 3-D imaging study has succeeded in producing an interactive software permitting individual as well as large group visualisation (with the use of a video projector) of tibia and fibula interactions with talus, as well as movements of tarsal and metatarsal bones during the different support phases in walking. Positions and roles of ligaments have also been illustrated. Subsequent laboratory experiments have demonstrated that intermediate-term retention of knowledge is favored in teaching when using this computer-assisted technique. Actually, in a test-retest situation, intermediate retention decreased by 10.87% when using traditional teaching; the decrease in retention was only a slight 0.450 /0 when using this 3-D imaging program as a visualisation aid. Sports training and coaching have also benefitted from the use of this tool

Are feeding preferences of white-tailed deer related to plant constituents?

Controlled feeding experiments can provide valuable insights into food selection of herbivores. We conducted cafeteria trials on captive yearling white-tailed deer (Odocoileus virginianus) during 2 years to determine feeding preferences in relation to plant chemical constituents, i.e., nitrogen and fibers. We simultaneously offered 8 species of cultivated and wild plants in monthly foraging trials conducted from June to October. We predicted that species preferences would be positively related to protein content from June to August and to digestible energy in September and October. As predicted, crude protein (CP) was positively related to feeding preferences, particularly as summer progressed. Feeding preferences were also negatively related to fiber content, especially in early summer. Our results indicate high protein needs over the complete growing season for yearling deer but a decrease in overall plant selectivity as summer progresses. Our results also suggest that deer browsing on cultivated plants might be due to higher CP content of cultivated plants than wild plants. To prevent deer impact on crops, managers should favor regeneration of plants rich in CP content in forests

A Total Evidence Approach to Understanding Phylogenetic Relationships and Ecological Diversity in Selanginella subg. Tetragonostachys

• Premise of the Study: Several members of Selaginella are renowned for their ability to survive extreme drought and “resurrect” when conditions improve. Many of these belong to subgenus Tetragonostachys , a group of ~45 species primarily found in North and Central America, with substantial diversity in the Sonoran and Chihuahuan Deserts. We evaluated the monophyly and the age of subgenus Tetragonostachys and assess how drought tolerance contributed to the evolution of this clade. • Methods: Our study included most Tetragonostachys species, using plastid and nuclear sequences, fossil and herbarium records, and climate variables to describe the species diversity, phylogenetic relationships, divergence times, and climatic niche evolution in the subgenus. • Key Results: We found that subgenus Tetragonostachys forms a monophyletic group sister to Selaginella lepidophylla and may have diverged from other Selaginella because of a Gondwanan–Laurasian vicariance event ca. 240 mya. The North American radiation of Tetragonostachys appears to be much more recent and to have occurred during the Early Cretaceous–late Paleocene interval. We identifi ed two signifi cant and nested ecological niche shifts during the evolution of Tetragonostachys associated with extreme drought tolerance and a more recent shift to cold climates. Our analyses suggest that drought tolerance evolved in the warm deserts of southwest North America and may have been advantageous for colonization of cold and dry boreal climates. • Conclusions: Our investigation provides a foundation for future research addressing the genomics of ecological niche evolution and the potential role of reticulate evolution in Selaginella subgenus Tetragonostachys .The authors thank P. Korall for sharing data. S. Buerki, N. Alvarez, and B. Marazzi provided technical assistance and valuable comments on the manuscript. N.A. was funded by the Swiss National Science Foundation (grant no. PBNEP3-132747). C.L.A. was funded by the Swedish Research Council

Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves

Kepler provides light curves of 156,000 stars with unprecedented precision. However, the raw data as they come from the spacecraft contain significant systematic and stochastic errors. These errors, which include discontinuities, systematic trends, and outliers, obscure the astrophysical signals in the light curves. To correct these errors is the task of the Presearch Data Conditioning (PDC) module of the Kepler data analysis pipeline. The original version of PDC in Kepler did not meet the extremely high performance requirements for the detection of miniscule planet transits or highly accurate analysis of stellar activity and rotation. One particular deficiency was that astrophysical features were often removed as a side-effect to removal of errors. In this paper we introduce the completely new and significantly improved version of PDC which was implemented in Kepler SOC 8.0. This new PDC version, which utilizes a Bayesian approach for removal of systematics, reliably corrects errors in the light curves while at the same time preserving planet transits and other astrophysically interesting signals. We describe the architecture and the algorithms of this new PDC module, show typical errors encountered in Kepler data, and illustrate the corrections using real light curve examples.Comment: Submitted to PASP. Also see companion paper "Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction" by Jeff C. Smith et a

Use of groundwater lifetime expectancy for the performance assessment of a deep geologic radioactive waste repository:2. Application to a Canadian Shield environment

Cornaton et al. [2007] introduced the concept of lifetime expectancy as a performance measure of the safety of subsurface repositories, based upon the travel time for contaminants released at a certain point in the subsurface to reach the biosphere or compliance area. The methodologies are applied to a hypothetical but realistic Canadian Shield crystalline rock environment, which is considered to be one of the most geologically stable areas on Earth. In an approximately 10\times10\times1.5 km3 hypothetical study area, up to 1000 major and intermediate fracture zones are generated from surface lineament analyses and subsurface surveys. In the study area, mean and probability density of lifetime expectancy are analyzed with realistic geologic and hydrologic shield settings in order to demonstrate the applicability of the theory and the numerical model for optimally locating a deep subsurface repository for the safe storage of spent nuclear fuel. The results demonstrate that, in general, groundwater lifetime expectancy increases with depth and it is greatest inside major matrix blocks. Various sources and aspects of uncertainty are considered, specifically geometric and hydraulic parameters of permeable fracture zones. Sensitivity analyses indicate that the existence and location of permeable fracture zones and the relationship between fracture zone permeability and depth from ground surface are the most significant factors for lifetime expectancy distribution in such a crystalline rock environment. As a consequence, it is successfully demonstrated that the concept of lifetime expectancy can be applied to siting and performance assessment studies for deep geologic repositories in crystalline fractured rock settings.Comment: 14 pages, 14 figures; Water Resources Research, Vol. 44, 200

Scaling migrations to communities: An empirical case of migration network in the Arctic

Seasonal migrants transport energy, nutrients, contaminants, parasites and diseases, while also connecting distant food webs between communities and ecosystems, which contributes to structuring meta-communities and meta-ecosystems. However, we currently lack a framework to characterize the structure of the spatial connections maintained by all migratory species reproducing or wintering in a given community. Here, we use a network approach to represent and characterize migratory pathways at the community level and provide an empirical description of this pattern from a High-Arctic terrestrial community. We define community migration networks as multipartite networks representing different biogeographic regions connected with a focal community through the seasonal movements of its migratory species. We focus on the Bylot Island High-Arctic terrestrial community, a summer breeding ground for several migratory species. We define the non-breeding range of each species using tracking devices, or range maps refined by flyways and habitat types. We show that the migratory species breeding on Bylot Island are found across hundreds of ecoregions on several continents during the non-breeding period and present a low spatial overlap. The migratory species are divided into groups associated with different sets of ecoregions. The non-random structure observed in our empirical community migration network suggests evolutionary and geographic constraints as well as ecological factors act to shape migrations at the community level. Overall, our study provides a simple and generalizable framework as a starting point to better integrate migrations at the community level. Our framework is a far-reaching tool that could be adapted to address the seasonal transport of energy, contaminants, parasites and diseases in ecosystems, as well as trophic interactions in communities with migratory species