Avida: a software platform for research in computational evolutionary biology

Avida is a software platform for experiments with self-replicating and evolving computer programs. It provides detailed control over experimental settings and protocols, a large array of measurement tools, and sophisticated methods to analyze and post-process experimental data. We explain the general principles on which Avida is built, as well as its main components and their interactions. We also explain how experiments are set up, carried out, and analyzed

Multi-bot Easy Control Hierarchy

The goal of our project is to create a software architecture that makes it possible to easily control a multi-robot system, as well as seamlessly change control modes during operation. The different control schemes first include the ability to implement on-board and off-board controllers. Second, the commands can specify either actuator level, vehicle level, or fleet level behavior. Finally, motion can be specified by giving a waypoint and time constraint, a velocity and heading, or a throttle and angle. Our code is abstracted so that any type of robot - ranging from ones that use a differential drive set up, to three-wheeled holonomic platforms, to quadcopters - can be added to the system by simply writing drivers that interface with the hardware used and by implementing math packages that do the required calculations. Our team has successfully demonstrated piloting a single robots while switching between waypoint navigation and a joystick controller. In addition, we have demonstrated the synchronized control of two robots using joystick control. Future work includes implementing a more robust cluster control, including off-board functionality, and incorporating our architecture into different types of robots

An examination of walking track analysis footprints of right-side unoperated limbs in rats prior to and following peripheral nerve injury and PEG fusion repair

Peripheral nerve injury can result in long-lasting functional deficits in humans due to mammals’ limited axon regenerative capacity. PEG fusion is a defined technique that fuses injured axons, resulting in morphological and electrophysiological continuity. The technology has been shown to restore lost behaviors due to peripheral nerve injury. The process involves an invasive surgical procedure on the left hind limb of female Sprague-Dawley rats that results in the severance of the sciatic nerve. Assessing behavioral recovery is perhaps the most important metric by which to quantify PEG fusion’s success. Recovery is most accurately and best assessed using the Sciatic Functional Index walking track analysis, or SFI. This procedure involves having a rat run up a path with its paws inked, and subsequent analysis compares the print length, toe spread, and intermediate toe spread of the “normal” and unoperated side (right) with the “experimental” and operated side (left). In this paper, we examine if surgical intervention and sciatic nerve transection on the left, experimental limb in rats results in significantly altered measurements on the right, unoperated side compared to pre-op, baseline measurements. Comparisons are made between baseline normal prints, normal prints three days post-op, and normal prints 42 days post-op for PEG-fused animals. Differences may exist due to altered gait after operation, physiological effects of surgical intervention, or random variation in the SFI testing paradigm. Regardless, attempting to highlight such discrepancies can contribute to developing better models for measuring recovery following peripheral nerve injury in mammals. Such models would more accurately be able to predict the clinical translatability of potential treatments for these nerve injuries. Analysis of SFI measurements pre- and post-op suggests that surgical intervention on the left experimental hind limb of rats does result in statistically significant differences in measured print length, toe spread, and intermediate toe spread post-op. In addition, we found that the differences between baseline and post-op measurements seem to become mitigated over time.Neuroscienc

The Effect of Various Pigments and Binders on Coated Gloss, Print Gloss, and Delta Gloss

The objective of this thesis is to determine the effects that various pigments and binders have on the coated gloss, print gloss, and delta gloss values. The effects of coat weight and calendering on the glossing response of the sheet will also be determined. Supplemental tests such as Parker Print Surf Roughness, brightness, and opacity will be measured to further evaluate the coating formulations. A total eight different coating formulations were made using four very common pigments and two latex binders. The four pigments used were #2 clay (100%), calcined clay (15% substitution), delaminated clay (25% substitution), and calcium carbonate (100%). The two latex binders used were styrene butadiene (SBR) and polyvinyl acetate (PVAC). Latex binders were chosen because their gloss response when applied in coatings is better than starch or protein binders. In order to isolate the effect of the pigment and binders a number of variables were held constant or within the same range. The solids levels of all coatings was adjusted to 62%. The binder ratio used was 12% based on dry parts pigment. The Brookfield viscosity was adjusted within the same range using polyacrylate. The printing ink and the print conditions were held constant also. The ink used was a low viscosity water based flexographic ink. A low gloss ink was chosen in order to eliminate the effects of the ink on the print gloss. When pigments are used alone in coating formulations, their particle size has the most dramatic effect on the gloss response of the sheet. The finer particles create a more optically smooth sheet therefore giving higher gloss values. When binders are introduced into the sheet, the pigment to binder particle interaction also plays a major role. A coat weight increase of 5 g/m^2 gave an average increase in coated gloss of 10% and gave a 20% increase in calendered gloss. The delaminated clay using the PVAC as the binder showed the highest gloss response due to an increase in coat weight. Calendering the sheet improved all gloss values. The effect was greater for coated gloss than for the print gloss. This was desired because it proves that the gloss of ink did not contribute to the print gloss but that it was the coating structure that affected the gloss response. The effect of pigment and binder type varied depending upon the combination used. The calcined clay gave the highest calendered gloss values which was not expected. However, when these samples were printed they displayed the highest delta gloss. This is due to the large particle size of the calcined clay. High delta gloss values are not desired because they produce a contrast between the image of the coating and the printed image. The pigment-binder interaction played a major role in determining the gloss response. When the PVAC binder was used, the delaminated clay gave the best gloss response with a delta gloss value of near zero (.2). When the SBR was used, the #2 clay gave the best response in gloss response. This was expected because the SBR latex is known for its high gloss response. A more detailed description and interpretation of the results can be found in the results and discussion section

Python for Archivists: Breaking Down Barriers Between Systems

[Excerpt] Working with a multitude of digital tools is now a core part of an archivist’s skillset. We work with collection management systems, digital asset management systems, public access systems, ticketing or request systems, local databases, general web applications, and systems built on smaller systems linked through application programming interfaces (APIs). Over the past years, more and more of these applications have evolved to meet a variety of archival processes. We no longer expect a single tool to solve all our needs and embraced the “separation of concerns” design principle that smaller, problem-specific and modular systems are more effective than large monolithic tools that try to do everything. All of this has made the lives of archivists easier and empowered us to make our collections more accessible to our users. Yet, this landscape can be difficult to manage. How do we get all of these systems that rely on different software and use data in different ways to talk to one another in ways that help, rather than hinder, our day to day tasks? How do we develop workflows that span these different tools while performing complex processes that are still compliant with archival theory and standards? How costly is it to maintain these relationships over time as our workflows evolve and grow? How do we make all these new methods simple and easy to learn for new professionals and keep archives from being even more esoteric