Individual attitudes towards trade: Stolper-Samuelson revisited

This paper studies to what extent individuals form their preferences towards trade policies along the lines of the Stolper-Samuelson logic. We employ a novel international survey data set with an extensive coverage of high-, middle-, and low-income countries, address a subtle methodological shortcoming in previous studies and condition on aspects of individualenlightenment. We find statistically significant and economically large Stolper-Samuelson effects. In the United States, being high-skilled increases an individual's probability of favoring free trade by up to twelve percentage points, other things equal. In Ethiopia, the effect amounts to eight percentage points, but in exactly the opposite direction. --Trade policy,Voter preferences,Political economy

On the Ground Validation of Online Diagnosis with Twitter and Medical Records

Social media has been considered as a data source for tracking disease. However, most analyses are based on models that prioritize strong correlation with population-level disease rates over determining whether or not specific individual users are actually sick. Taking a different approach, we develop a novel system for social-media based disease detection at the individual level using a sample of professionally diagnosed individuals. Specifically, we develop a system for making an accurate influenza diagnosis based on an individual's publicly available Twitter data. We find that about half (17/35 = 48.57%) of the users in our sample that were sick explicitly discuss their disease on Twitter. By developing a meta classifier that combines text analysis, anomaly detection, and social network analysis, we are able to diagnose an individual with greater than 99% accuracy even if she does not discuss her health.Comment: Presented at of WWW2014. WWW'14 Companion, April 7-11, 2014, Seoul, Kore

Design, fabrication and implementation of a flexure-based micropositioner for Dip Pen Nanolithography

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 40).Dip Pen Nanolithography (DPN) takes the concept of a quill-tip pen and shrinks it to the nanometer scale. DPN uses a machine to pick up and deposit proteins and liquids in arrays. A problem with the machine however is aligning the pen tip relative to the machine. Currently, it is aligned manually, which is time and labor intensive. It would drastically increase productivity and throughput if a machine was developed that could perform this task accurately and repeatedly. This would also allow quick tool changes for experiments involving multiple DPN processes. The impact of this alignment machine is that it solves problems not only for DPN machines, but also for atomic force microscopes and similar instruments. This thesis is about the design and implementation of this alignment machine. The user would arbitrarily place the pen tip on a ball mount. The ball mount would have three holes that are larger than three balls. The balls are held stationary, while the ball mount can move over it. An overhead camera is used to determine the actual and desired position of the ball mount relative to the balls. Once the ball mount reaches its desired position, the balls are glued in place using UV-cured epoxy. This half of a kinematic coupling would then attach to the other half of a kinematic coupling on the DPN machine. The repeatability of the ball mount holder was tested and has an in-plane 1[sigma] translational repeatability of 15.9 [mu]m and 0.0122 rad. This can be improved and further work is suggested.by Marcel A. C. Thomas.S.B

Non-invasive monitoring of renal transplant recipients: Urinary excretion of soluble adhesion molecules and of the complement-split product C4d

Background: The number of inducible adhesion molecules known to be involved in cell-mediated allograft rejection is still increasing. In addition, recent data describe complement activation during acute humoral allograft rejection. The aim of this study was to assess whether specific molecules from either pathway are excreted into urine and whether they can provide useful diagnostic tools for the monitoring of renal transplant recipients. Methods: Urinary concentrations of soluble adhesion molecules (sICAM-1, sVCAM-1) and of the complement degradation product C4d were determined by standardized ELISA technique in 75 recipients of renal allografts and 29 healthy controls. Patient samples were assigned to four categories according to clinical criteria: group 1: acute steroid-sensitive rejection (ASSR, n=14), group 2: acute steroid-resistant rejection (ASRR, n=12), group 3: chronic allograft dysfunction (CAD, n=20) and group 4: stable graft function (SGF, n=29). Results: All patients with rejection episodes (groups 1-3) had significantly higher values of urinary sC4d compared with healthy controls and patients with stable graft function (p<0.05). The urinary levels of sVCAM-1 were significantly higher in group 2 (ASRR) compared with all other groups (p<0.001). Uniformly low amounts of s-VCAM-1 and complement-split product C4d were excreted by healthy controls (group 0). In contrast, urinary sICAM-1 concentration in healthy controls was almost as high as in group 2 (ASRR) whereas patients with a stable functioning graft (group 4) excreted significantly less sICAM-1 (p<0.05). Conclusion: The evaluation of sVCAM-1 and sC4d excretion in urine can provide a valuable tool with regard to the severity and type of allograft rejection. With respect to long-term allograft survival, serial measurements of these markers should have the potential to detect rejection episodes and prompt immediate treatment. Copyright (C) 2003 S. Karger AG, Basel

Estimating Real Production and Expenditures Across Nations: A Proposal for Improving the Penn World Tables

In this paper we propose a new approach to international comparisons of real GDP measured from the output-side. The traditional Geary-Khamis system to measure real GDP from the expenditure-side is modified to include differences in the terms of trade between countries. It is shown that this system has a strictly positive solution under mild assumptions. On the basis of a set of domestic final output, import and export prices and values for 14 European countries and the U.S. it is shown that differences between real GDP measured from the expenditure and output-side can be substantial, especially for small open economies.