Calibration standard for dynamic evaluation of a profile-plotter

Template is used for evaluation of the dynamic characteristics and accuracy of the plotter. It has a profile composed of surfaces parallel to and at known distances from a reference plane, plane, the diverse surfaces being connected by slopes of known angles and blended by cylindrical developments of known radii

Design of a Self-Resetting, Low-Maintenance, Long-Term Bait Station for Rodent Control

A low-maintenance, long-term bait station that resets itself after being triggered would be a very useful tool for controlling Richardson’s ground squirrels, or other problem rodent species, in remote locations. With collaborators, we developed and tested two such devices using lab rats in pen settings. The devices can be left in-situ for long periods of time without servicing, and requires only occasional bait and/or battery replacement. Squirrels would be unable to cache bait due to the integrated time-out mechanism. The devices use capacitive sensor or strain gauge systems for animal identification, making it very unlikely that smaller non-target species would be able to trigger the systems while the design precludes entry by larger non-target species. Further refinement and testing will be needed before a viable, commercial product can go into production. These refinements include increasing reliability, reducing power requirements, design features and triggering mechanisms tightly linked to the attributes of the targeted pest species, and reduction of production costs. The devices will also need to be tested in field settings for extended periods of time

Agile Project Dynamics: A System Dynamics Investigation of Agile Software Development Methods

While Agile software development has many advocates, acceptance in the government and defense sectors has been limited. To address questions of meanings to the term “Agile,” we examine a range of Agile methods practiced and develop a framework of seven characteristics, which we call the Agile Genome. We gain insight into the dynamics of how Agile development compares to classic “waterfall” approaches by constructing a System Dynamics model for software projects. The Agile Project Dynamics (APD) model captures each of the Agile genes as a separate component of the model and allows experimentation with combinations of practices and management policies. Experimentation with the APD model is used to explore how different genes work in combination with one another to produce both positive and negative effects. The extensible design of the APD model provides the basis for further study of Agile methods and management practices

Elastic cavitation, tube hollowing, and differential growth in plants and biological tissues

Elastic cavitation is a well-known physical process by which elastic materials under stress can open cavities. Usually, cavitation is induced by applied loads on the elastic body. However, growing materials may generate stresses in the absence of applied loads and could induce cavity opening. Here, we demonstrate the possibility of spontaneous growth-induced cavitation in elastic materials and consider the implications of this phenomenon to biological tissues and in particular to the problem of schizogenous aerenchyma formation

Evaluation of a Food Bait Block for Potential Chemical Delivery to Black-tailed Prairie Dogs (\u3ci\u3eCynomys ludovicianus\u3c/i\u3e)

Fertility control is a potential method to control prairie dog populations in the urban/suburban environment. However, an effective, oral delivery system is needed. We tested a food bait block delivery system that could make baits available to prairie dogs over a number of days which would make this method more cost-effective than placing food bait by hand near burrows every day. Prairie dogs readily consumed the bait blocks stacked on vertical metal poles during the day. We found, however, that rabbits and mice also consumed the food bait blocks, mainly at night. Over the course of the study, the mean amount removed per site was 81% of the food bait presented. However, to make the food bait blocks primarily available to prairie dogs, a device that would eliminate access to the food bait blocks at night is needed