Friction Test Machine

Parker Aerospace is interested in collecting empirical data of friction coefficients for skewed roller bearings. A fixture will be designed, constructed and tested to allow a technician to quickly and easily measure the friction torque of a skew roller bearing with varying axial loads, geometries, lubricants, temperatures and rotational speeds in order to improve actuator efficiency

Temporal Discounting of Losses

This dissertation presents a series of five papers to better understand how to measure discounting, how and why discounting of losses differs from discounting of gains, and how to apply research on discounting to public policy. Paper 1 compares two common methods of measuring discounting - titration and matching - with a dynamic "multiple staircase" method adapted from psychophysics. Paper 2 examines the robustness of the sign effect across financial, environmental, and health domains. Paper 3 explores the interaction of sign and magnitude, and offers an explanation for why losses reverse or eliminate the magnitude effect. Paper 4 investigates an explanation for the sign effect: that dread looms larger than pleasurable anticipation, and Paper 5 offers an integrative approach to intertemporal choice, with recommendations for environmental policy. Taken together, these investigations suggest that discounting of losses is both quantitatively and qualitatively different from discounting of gains. Across domains and methods losses are discounted much less than gains and losses eliminate (or reverse) the magnitude effect. These behavioral differences occur because "dread" of losses is more pronounced than pleasurable anticipation of gains. In other words, people dislike having losses hanging over their heads more than they enjoy looking forward to positive events. For this reason, while people almost universally want to have gains immediately (due to impatience and other reasons), people are divided about losses - sometimes preferring to realize them immediately, and sometimes preferring to postpone them. Theories and policies involving intertemporal choice must distinguish between losses and gains if they hope to accurately describe and predict people's choices

Macrophages from gut-corrected CF mice express human CFTR and lack a pro-inflammatory phenotype

Macrophages represent prominent immune orchestrators of cystic fibrosis (CF) inflammation and, as such, are an ever-increasing focus of CF research with several reports of intrinsic immune dysfunction related to loss of CFTR activity in macrophages themselves. Animal models of CF have contributed, in no small part, to a deepening of our understanding of the pathophysiology of the disease and towards therapeutic development. A commonly-used animal model in CF research is the Cftr(tm1Unc) Tg(FABP-hCFTR) mouse, which displays gut-specific expression of a human CFTR transgene in order to rescue the high rate of early mortality in Cftr-null mice associated with severe intestinal obstruction. We find significant variation in the response to inflammatory challenge of patient macrophages and cells derived from the Cftr(tm1Unc) Tg(FABP-hCFTR) mouse and show that macrophages derived from this mouse exhibit aberrant expression of human CFTR. This may contribute to the absence of inflammatory changes in this model

Understanding and neutralizing the expense prediction bias : the role of accessibility, typicality, and skewness

This work was funded by the Social Sciences and Humanities Research Council of Canada, True North Communications Inc. Faculty Research Funds at The University of Chicago Booth School of Business, and the Mays Business School Dean’s Office.Consumers display an expense prediction bias in which they underpredict their future spending. The authors propose this bias occurs in large part because: 1) consumers base their predictions on typical expenses that come to mind easily during prediction, 2) taken together, typical expenses lead to a prediction near the mode of a consumer’s expense distribution rather than the mean, and 3) expenses display positive skew with mode < mean. Accordingly, the authors also propose that prompting consumers to consider reasons why their expenses might be different than usual increases predictions – and therefore prediction accuracy – by bringing atypical expenses to mind. Ten studies (N = 6,044) provide support for this account of the bias and the “atypical intervention” developed to neutralize it.Publisher PDFPeer reviewe

The Outcome of Neutrophil-T Cell Contact Differs Depending on Activation Status of Both Cell Types

Neutrophils and T cells exist in close proximity in lymph nodes and inflamed tissues duringhealth and disease. They are able to form stable interactions, with profound effects on thephenotype and function of the T cells. However, the outcome of these effects arefrequently contradictory; in some systems neutrophils suppress T cell proliferation, inothers they are activatory or present antigen directly. Published protocols modelling theseinteractions in vitro do not reflect the full range of interactions found in vivo; they do notexamine how activated and naïve T cells differentially respond to neutrophils, or whetherde-granulating or resting neutrophils induce different outcomes. Here, we established aculture protocol to ask these questions with human T cells and autologous neutrophils.We find that resting neutrophils suppress T cell proliferation, activation and cytokineproduction but that de-granulating neutrophils do not, and neutrophil-releasedintracellular contents enhance proliferation. Strikingly, we also demonstrate that T cellsearly in the activation process are susceptible to suppression by neutrophils, while laterstage T cells are not, and naïve T cells do not respond at all. Our protocol therefore allowsnuanced analysis of the outcome of interaction of these cells and may explain thecontradictory results observed previously

SERS Microsensors for the Study of pH Regulation in Cystic Fibrosis Patient-Derived Airway Cultures

Acidification of the airway surface liquid in the respiratory system could play a role in the pathology of Cystic Fibrosis, but its low volume and proximity to the airway epithelium make it a challenging biological environment in which to noninvasively collect pH measurements. To address this challenge, we explored surface enhanced Raman scattering microsensors (SERS-MS), with a 4-mercaptobenzoic acid (MBA) pH reporter molecule, as pH sensors for the airway surface liquid of patient-derived in vitro models of the human airway. Using air–liquid interface (ALI) cultures to model the respiratory epithelium, we show that SERS-MS facilitates the optical measurement of trans-epithelial pH gradients between the airway surface liquid and the basolateral culture medium. SERS-MS also enabled the successful quantification of pH changes in the airway surface liquid following stimulation of the Cystic Fibrosis transmembrane conductance regulator (CFTR, the apical ion channel that is dysfunctional in Cystic Fibrosis airways). Finally, the influence of CFTR mutations on baseline airway surface liquid pH was explored by using SERS-MS to measure the pH in ALIs grown from Cystic Fibrosis and non-Cystic Fibrosis donors

Using the stated preference method for the calculation of social discount rate

The aim of this paper is to build the stated preference method into the social discount rate methodology. The first part of the paper presents the results of a survey about stated time preferences through pair-choice decision situations for various topics and time horizons. It is assumed that stated time preferences differ from calculated time preferences and that the extent of stated rates depends on the time period, and on how much respondents are financially and emotionally involved in the transactions. A significant question remains: how can the gap between the calculation and the results of surveys be resolved, and how can the real time preferences of individuals be interpreted using a social time preference rate. The second part of the paper estimates the social time preference rate for Hungary using the results of the survey, while paying special attention to the pure time preference component. The results suggest that the current method of calculation of the pure time preference rate does not reflect the real attitudes of individuals towards future generations

Time preferences and risk aversion: tests on domain differences

The design and evaluation of environmental policy requires the incorporation of time and risk elements as many environmental outcomes extend over long time periods and involve a large degree of uncertainty. Understanding how individuals discount and evaluate risks with respect to environmental outcomes is a prime component in designing effective environmental policy to address issues of environmental sustainability, such as climate change. Our objective in this study is to investigate whether subjects' time preferences and risk aversion across the monetary domain and the environmental domain differ. Crucially, our experimental design is incentivized: in the monetary domain, time preferences and risk aversion are elicited with real monetary payoffs, whereas in the environmental domain, we elicit time preferences and risk aversion using real (bee-friendly) plants. We find that subjects' time preferences are not significantly different across the monetary and environmental domains. In contrast, subjects' risk aversion is significantly different across the two domains. More specifically, subjects (men and women) exhibit a higher degree of risk aversion in the environmental domain relative to the monetary domain. Finally, we corroborate earlier results, which document that women are more risk averse than men in the monetary domain. We show this finding to, also, hold in the environmental domain