A low power high power supply rejection ratio bandgap reference for portable applications

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 86-87).A multistage bandgap circuit with very high power supply rejection ratio was designed and simulated. The key features of this bandgap include multiple power modes, low power consumption and a novel resistor trimming strategy. This design was completed in deep submicron CMOS technology, and is especially suited for portable applications. The bandgap designed achieves over 90 dB of power supply rejection and less than 17 microvolts of noise without any external filtering. With an external filtering capacitor, this performance is significantly enhanced. In addition, the design includes an efficient voltage-to-current converter and a fast-charge circuit for charging the external capacitor.by Siddharth Sundar.M.Eng

Design of a Prediction Game in the Domain of Computer Security

Prediction Games are games where players analyze historical data and make predictions about future events. The predictions are scored which gives the players an idea of where they stand. This game is appropriate for domains where data is coming in frequently and where there is a decent quantity of historical data for participants to explore. Knowledge in Computer Security carries high value personally and professionally and statistics in this data domain is collected by many organizations for various reasons. This thesis explores the design of a prediction game in the field of Computer Security. The goals of this project include identifying data sets that could be used for a prediction game, designing a prediction activity which will be helpful to players, and developing a prototype version of the prediction game. A heuristic evaluation of the prototype will provide feedback for improvements to the game mechanics such as user interface and data visualizations. At the end of the project, there will be a greater understanding of the availability of computer security data, how it can be used for developing prediction games, and tradeoffs in the design of computer security prediction games

3-Dimensional Mapping and Radiofrequency Ablation of Atrial Flutter in a Patient with Interrupted Inferior Vena Cava

The presence of isolated interrupted inferior vena cava (IVC) is very rare. Though the occurrence of typical atrial flutter in this setting has recently been described, the use of 3-dimensional activation mapping to aid the management of such patients has not yet been described. We report the successful ablation of this arrhythmia in a 63-year-old woman using the superior route through the internal jugular vein with the help of a mapping system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46349/1/10840_2005_Article_4512.pd

Design of a Prediction Game in the Domain of Computer Security

Prediction Games are games where players analyze historical data and make predictions about future events. The predictions are scored which gives the players an idea of where they stand. This game is appropriate for domains where data is coming in frequently and where there is a decent quantity of historical data for participants to explore. Knowledge in Computer Security carries high value personally and professionally and statistics in this data domain is collected by many organizations for various reasons. This thesis explores the design of a prediction game in the field of Computer Security. The goals of this project include identifying data sets that could be used for a prediction game, designing a prediction activity which will be helpful to players, and developing a prototype version of the prediction game. A heuristic evaluation of the prototype will provide feedback for improvements to the game mechanics such as user interface and data visualizations. At the end of the project, there will be a greater understanding of the availability of computer security data, how it can be used for developing prediction games, and tradeoffs in the design of computer security prediction games

Supramolecular Corrals on Surfaces Resulting from Aromatic Interactions of Nonplanar Triazoles

Interaction forces between aromatic moieties, often referred to as π–π interactions, are an important element in stabilizing complex supramolecular structures. For supramolecular self-assembly occurring on surfaces, where aromatic moieties are typically forced to adsorb coplanar with the surface, the possible role of intermolecular aromatic interactions is much less explored. Here, we report on unusual, ring-shaped supramolecular corral surface structures resulting from adsorption of a molecule with nonplanar structure, allowing for intermolecular aromatic interactions. The discrete corral structures are observed using high-resolution scanning tunneling microscopy, and the energetic driving forces for their formation are elucidated using density functional theory calculations and Monte Carlo simulations. The individual corrals involve between 11 and 18 molecules bound through triazole moieties to a ring-shaped ensemble of bridge site positions on (111) surfaces of copper, silver, or gold. The curvature required to form the corrals is identified to result from the angle dependence of aromatic interactions between molecular phenanthrene moieties. The study provides detailed quantitative insights into triazole−surface and aromatic interactions and illustrates how they may be used to drive surface supramolecular self-assembly

Interleukin 2 is an Upstream Regulator of CD4+ T Cells from Visceral Leishmaniasis Patients with Therapeutic Potential

Control of visceral leishmaniasis (VL) caused by Leishmania donovani requires interferon-γproduction by CD4+ T cells. In VL patients, antiparasitic CD4+ T-cell responses are ineffective for unknown reasons. In this study, we measured the expression of genes associated with various immune functions in these cells from VL patients and compared them to CD4+ T cells from the same patients after drug treatment and from endemic controls. We found reduced GATA3, RORC, and FOXP3 gene expression in CD4+ T cells of VL patients, associated with reduced Th2, Th17, and FOXP3+CD4+ T regulatory cell frequencies in VL patient blood. Interleukin 2 (IL-2) was an important upstream regulator of CD4+ T cells from VL patients, and functional studies demonstrated the therapeutic potential of IL-2 for improving antiparasitic immunity. Together, these results provide new insights into the characteristics of CD4+ T cells from VL patients that can be used to improve antiparasitic immune responses.</p