Huge breeding aggregations of red-sided garter snakes (Thamnophis sirtalis parietalis) at overwintering dens in Manitoba provide a unique opportunity to identify sources of mortality and to clarify factors that influence a snake's vulnerability to these factors. Comparisons of sexes, body sizes, and body condition of more than 1000 dead snakes versus live animals sampled at the same time reveal...

In a collection of 58 snakes comprising predominantly Eurasian vipers in Switzerland, five snakes died unexpectedly during hibernation from 2009 to 2012. In one snake, organisms resembling chlamydiae were detected by immunohistochemistry in multiple histiocytic granulomas. Real-time quantitative PCR and microarray analysis were used to determine the presence of Chlamydia pneumoniae in tissue sa...

We present a method for searching for achordal open paths (snakes) in n-dimensional hypercube graphs (the box). Our technique first obtains a set of exemplary snakes using an evolutionary algorithm. These snakes are then analyzed to define a pruning model that constrains the search space. A depth-first search of the constrained solution space has established new lower bounds for the length of t...

Modern snakes probably originated as habitat specialists, but it controversial unclear whether they were ancestrally terrestrial burrowers or marine swimmers. We used x-ray virtual models of the inner ear to predict the habit of Dinilysia patagonica, a stem snake closely related to the origin of modern snakes. Previous work has shown that modern snakes perceive substrate vibrations via their in...

Energy minimizing contours or snakes are tools for delineating objects of interest in an image. Snakes are defined discretely or in continuous form with continuous snakes having advantages over discrete snakes. A continuous snake called B-snake has been previously defined using B-spline curves. In this paper, a continuous snake called R-snake is introduced that is based on rational Gaussian (Ra...

Snakes have become a standard image analysis technique with several variants now in common use. We have developed a software package called “United Snakes”. It unifies the most important snake variants, including finite difference, B-spline, and Hermite polynomial snakes, within the framework of a general finite element formulation with a choice of shape functions. Furthermore, we have incorpor...