Using printer ink color to control the behavior of paper microfluidics.

Paper microfluidic devices (including lateral flow assays) offer an excellent combination of utility and low cost. Many paper microfluidic devices are fabricated using the Xerox ColorQube line of commercial wax-based color printers; the wax ink serves as a hydrophobic barrier to fluid flow. These printers are capable of depositing four different colors of ink, cyan (C), magenta (M), yellow (Y), and black (K), plus 11 combinations of these colors (CM, CY, CK, MY, MK, YK, CMY, CMK, CYK, MYK, and CMYK), although most researchers use only black ink to print paper microfluidic devices. Recently, as part of a project to develop a computer-aided design framework for use with paper microfluidics devices, we unexpectedly observed that different colors of wax ink behave differently in paper microfluidics. We found that among the single colors of ink, black ink actually had the most barrier failures, and magenta ink had the fewest barrier failures. In addition, some combinations of colors performed even better than magenta: the combinations CY, MK, YK, CMY, CYK and MYK had no barrier failures in our study. We also found that the printer delivers significantly different amounts of ink to the paper for the different color combinations, and in general, the color combinations that formed the strongest barriers to fluid flow were the ones that had the most ink delivered to the paper. This suggests that by simply weighing paper samples printed with all 15 combinations of colors, one can easily find the color combinations most likely to form a strong barrier for a given printer. Finally, to show that deliberate choices of ink colors can actually be used to create new functions in paper microfluidics, we designed and tested a new color-based "antifuse" structure that protects paper microfluidic devices from a typical operator error (addition of too much fluid to the device). Our results provide a set of color choice guidelines that designers can use to control the behavior of their paper microfluidics

Teaching Notes for CHAPTER 8: Right and Wrong, Balanced on the Edge of a Spear: U.S. Forces at a Mosque in Baghdad

Teaching Notes for Right and Wrong, Balanced on the Edge of a Spear: U.S. Forces at a Mosque in Baghdad, by Joshua Potter. The purpose of this case is to provide a framework to understand the complex operational environment facing a U.S. advisor team, and to equip the student to ask the right questions that will help him or her to be prepared. This case study will take students through the leadership challenges faced by an advisor team in Iraq. The discussions are intended to provide an understanding of local politics, including an appreciation for the expectations and needs of the people; to identify signs of corruption among host-nation partners; and to assess how military assets and resources can be used to improve the chances of operational success

Explaining Subnational Variation in Voter Coordination and Party Entry in Electoral Competition

This dissertation focuses on electoral politics in a comparative perspective, specifically subnational variation in strategic party entry and strategic voter coordination. The dissertation studies how within-country variation both in the demographic composition of electoral districts and also in the supply-side composition of ballots can impact: where parties choose to contest elections, which and how many parties are successful, and why some voters in a country might not have the option of casting a ballot for all parties on election day. The first and third papers concentrate specifically on the supply side of electoral competition and demonstrate under what circumstances parties can be expected to compete across a broad range of electoral districts. I find that parties strategically enter those electoral districts where they believe that the outcome of the previous election indicates the electoral market is out of equilibrium. I also find that certain types of political institutions can induce parties in some countries to enter more broadly across electoral districts. The second paper explores the interaction between supply and demand to assess the impact of electoral constituency diversity on electoral outcomes. In short, I find that there exists a statistically robust relationship between driving up diversity in an electoral district and subsequently increasing the number of party offerings voters have access to on election day. This relationship, however, is substantially qualified by the permissiveness of electoral institutions

Evaluating Executive Functions in a Proposed Animal Model of ADHD: Spontaneously Hypertensive Rats

Evaluating animal models of attention-deficit hyperactivity disorder (ADHD) is crucial for expanding the breadth of knowledge of the disorder. Spontaneously Hypertensive Rats (SHRs) have been used for several years as an animal model of ADHD, and routinely provide new information about aspects of the disorder that contribute to behavioral and pharmaceutical treatment interventions. Twelve male and 12 female SHRs as well as 12 male and 12 female Wistar-Kyoto rats (i.e., control strain for the SHR) were acquired and tested on a series of operant tests starting postnatal day (PND) 70. These tests consisted of measures of motor and executive function and include Differential Responding of High Rates (DRH) to assess possible deficits in response speed, Differential Responding of Low Rates (DRL) to assess impulsive action, and Delayed Spatial Alternation (DSA) to assess working memory. It was predicted that the SHRs would exhibit both inhibitory control and working memory deficits that would not be explained due to a motor deficit. The results indicated that SHRs had significant deficits in inhibitory control and working memory as indicated by their underperformance on DRL and DSA tasks (respectively) relative to the WKY rats. The results provide evidence supporting the use of the SHR as an animal model of ADHD and suggest their use in future research evaluating the neurobiological mechanisms associated with the neurodevelopmental disorder as well as comparison to other ADHD animal models is warranted

Modelling of heat emitters embedded within third order lumped parameter building envelope model

A dynamic modelling approach for heat emitters embedded within an existing third order lumped parameter building envelope model is reported in this work. The model has been found to provide more accurate results with negligible expense of computational time compared to a conventional quasi-dynamic model. The dynamic model also is preferred over the quasi-dynamic model as it allows for modelling emitters with high thermal capacity such as under-floor heating. Recommendation for this approach is justified through a series of analyses and comparative tests for various circuit options, timesteps and control volumes

A New Model of Trend Inflation

This paper introduces a new model of trend (or underlying) inflation. In contrast to many earlier approaches, which allow for trend inflation to evolve according to a random walk, ours is a bounded model which ensures that trend inflation is constrained to lie in an interval. The bounds of this interval can either be fixed or estimated from the data. Our model also allows for a time-varying degree of persistence in the transitory component of inflation. The bounds placed on trend inflation mean that standard econometric methods for estimating linear Gaussian state space models cannot be used and we develop a posterior simulation algorithm for estimating the bounded trend inflation model. In an empirical exercise with CPI inflation we find the model to work well, yielding more sensible measures of trend inflation and forecasting better than popular alternatives such as the unobserved components stochastic volatility model.